Building Water Supply. Flashcards
- When was #3 tunnel for NYC water supply start to build?
1970.
- Weight of 4” EXCI 1/8 bend?
1.55 lb.
- How long did it take to compleat tunnel #1 for NYC water supply?
6 years.
- EPA?
Environment protection agency (federal).
- Parts of New York City’s water supply system?
- Croton watershed ( reservoirs, lakes), Croton aqueduct.
- Catskills watershed, tunnels and aqueducts.
- Delaware watershed, tunnels and aqueducts.
- What is potable water?
That is suitable for human consumption.
- Can water, which contain impurities , be made potable?
All water can be treated so as not to be harmful, water from some sources is not affordable for treatment because of the excessive cost of purifying it .
- List three principal sources of water supply for municipalities?
- Rivers.
- Lakes.
- Wells.
- Why are wells the most common source of individual water supply?
Municipal water supply systems contain many miles of pipe to convey water from its source to the consumer. A well taps a source close to (usually on the property) where the water is to be used.
- List four types of water wells?
- Dug well.
- Bored well.
- Driven well.
- Drilled well.
- Three methods of drilling wells?
- Cable tool.
- Rotary.
- Water and air jetted method.
- What is the recommended depth of a drilled well when the water and jetted method is used?
The recommended depth is 0 to 100 feet.
- How does pure water differ from potable water?
Pure water contains no impurities whereas potable water does contain some impurities.
- What is pure water?
An odorless, colorless, tasteless, transparent liquid which contains two parts hydrogen and one part oxygen.
- What is potable water?
Colorless, pleasing to the taste and ell, free of harmful bacteria and free of excessive amounts of dissolved solids.
- Four major groups of the harmful impurities frequently found in untreated or raw water?
- Particles in suspension.
- Minerals (dissolved matter).
- Gases.
- Pathogenic microorganisms.
- How can impurities in water be removed or neutralized?
- Sedimentation.
- Filtration.
- Aeration.
- Addition of chemicals.
- What are the treatments of raw water?
- Sedimentation.
- Coagulation.
- Filtration.
- Chlorination.
- Fluoridation.
- pH adjustment.
- How can turbidity (cloudy) be removed from water?
- By sedimentation.
2. Use of alum as a coagulating agent to collect the dirt and suspended materials.
- How can the rate of settlement be increased in water treatment plant?
The water is agitated slowly by moving paddles assuring all suspended materials in the raw water come in contact with the alum.
- Describe the flow of water in sand filters of water treatment plant?
The water is first pumped to the large basins. It then flows slowly over the baffles, onto the sand filter bed. As the water filters through the sand, any remaining particles of suspended matter adhere to the grains of sand.
- What procedure s may be involved at the water treatment plant after filtration?
- Hydrofluosilicic acid (H2SiF6) may be added to inhibit tooth decay.
- Lime is added to increase the pH.
- Copper sulfate is added to destroy algae in the distribution reservoirs.
- Soda ash can be introduced into reservoirs to reduce acidity.
.23. How can suspended material be removed from an individual water supply?
By a pressure type filter (sand).
- Living organisms, which can be removed during filtration?
- Cysts.
- Algae.
- Bacteria.
- What results in the formation of dissolved gases (hydrogen sulfide, carbon dioxide) in water supply?
Decomposition of organic matter.
- How can dissolved gases be removed from water supply?
By aeration or degasification.
- What methods can be used to remove gases from water supply accept aeration?
- Adding chlorine.
- Adding activated carbon.
- Both methods require that the water be filtered after treatment.
- How can bacteria and viruses be killed?
- Boiling.
- Ultraviolet light.
- Chlorination.
- What method is used most frequently to kill bacteria and viruses in water supply?
Chlorination.
30.what test can be made if a specific problem arises that creates a situation of potential danger?
A fecal coliform test
- What does the term parts per million mean?
One part of a substance by weight, per million parts of water by weight.
- How are impurities in water measured?
- In ppm - parts per million.
- In mgl - milligrams per liter.
- In gpg - grains per gallons.
- What is a grain measurement?
A measurement of weight equal to 0.002285 oz.
- What does the symbol pH represent?
Express the intensity of the acid or alkaline condition of water.
- How does acid and alkaline conditions effect pH values?
Acid conditions decrease and alkaline increase pH values.
- What does the term pH identifies?
Concentration of hydrogen: active hydrogen ions within the hydrogen atom based on the gram-equivalent weight per liter of water.
- Why is important to know the pH value of the water chosen as a source of supply?
- Acid water is very corrosive.
2. Alkaline has a soda taste and leaves the skin feeling dry after use.
- How is water treated on a power boiler in anion and cation tanks?
They have to be regenerated using a solution of sulfuric acid and caustic soda.
- What are the common characteristics of both soft and hard water?
Soft water lathers easily, hard lathers with difficulty, leaving the hands rough and form a ring or scum in a lavatory or tub.
- What is responsible for water hardness?
Calcium and magnesium.
- What standards are available to determine whether or not the impurities found in water are at an acceptable level, either before or after treatment?
- By the water conditioning foundation.
2. By the EPA (environmental protection agency).
- A quality standard for water by the water conditioning foundation?
- Bacteria content and toxic substances to conform to public health drinking water standards published by the U. S. Public Health Service.
- Hardness 3.5 gpg.
- Iron and manganese 0.2 ppm.
- Turbidity 5.0 ppm.
- pH value 7.0 to 10.5.
- Taste and odor not objectionable.
- Hydrogen sulfide 1/10 ppm.
- Dissolved solids 30 gpg.
- Fluoride 1.5 ppm.
- Chloride and sulfate 250 ppm.
- Color - clear.
- The four characteristics of water quality designated by the EPA?
- Physical characteristics - taste, color, level of turbidity, temperature, and odor.
- Chemical content - hardened or softness.
- Biological ingredients - primarily microorganisms that have direct bearing on our health.
- Radiological substances must be avoided, as must any water that has in any way contracted radioactive materials.
- Parts of typical municipal treatment plant?
- Screens at raw water source.
- Sediment basin.
- Chlorination point 1.
- Alum point.
- Flocculation basin.
- Aeration or degasification.
- Chlorination point 2.
- Sand filters.
- What impurities are removed by coarse screens of water treatment plant?
The large pieces of debris such as logs.
- What impurities are removed at sediment tank?
The large-sized impurities that cause the water to be turbid (leaves, etc.).
- An average length of stay for raw water in the basin of municipal treatment plant?
1 1/2 days.
- The process, which occurs at point of adding alum and in the flocculation basin work together. Explain?
Alum is added to start the flocculation treatment process which take place in the flocculation basin. The impurities then settle to the bottom of the basin and are removed periodically. An awe rage length of retention at this basin is 5 hours.
- How can water be made to taste better?
Carbon filters (similar to charcoal) are added to the system. This method of treatment is expensive and is not widely used unless taste and smell are extreme.
- What is used to add a chlorine solution to an individual well water supply system?
A simple feed pump and regular laundry bleach.
- How is chlorine added to well water system?
Chemical feed pump start together with well pump and add chlorine to the feed pipe of pressure tank.
- What are the objectionable characteristics of hard water?
- No soap lather can be formed until hardness particles are coated.
- Calcium causes deposits within pipelines.
- What effects has the buildup scale in piping systems?
- Reduces the rate of heat transfer and efficiency of equipment.
- Reduces flow rate.
- Results in odor value operation.
- Increases power requirements.
- What must be done to watering some localities where it has a high mineral content?
The appliance generally used for the removal magnesium and calcium is a water softener that uses the ion-exchange principle.
- What is an ion?
An ion is an electrically charged atom or group of atoms.
- Siding the term zeolite?
A zeolite Is a solid which will interchange ions with hardness particles in a liquid and still retain its basic structure in water softening equipment.
- List groups and types of zeolites?
Organic. 1. Resinous. 2. Carbonaceous. Inorganic. 1. Green sand (glauconite). 2. Synthetic gel type.
- Use of different types of zeolites?
- Clear but hard water - synthetic gel up to about 12,000 grains per cubic foot.
- Hight temperature and pH, oxidizing conditions - resinous type up to about 35,000 grains on the sodium cycle.
- Low pH or iron bearing waters - glauconite up to about 3,000 grains per cubic foot.
- Aggressive waters, metallic cations at low concentrations - carbonaceous type about 800 grains per cubic foot.
- The five major components of water softening devices?
- Tank or shell.
- Control valve.
- Softening material.
- Gravel or sand filters.
- Strainers.
- What determines the size of the tank?
The gpm of softened water required and are available from 12”x40” to 84”x60”.
- What is a multiport valve?
A valve allows flow in more than one direction available in 2, 3”, 4”, or 6” sizes. A 6” multiport valve weights over 400l lb and thus requires extra support.
- Why is a layer of gravel or sand filters needed below the softening material?
It helps to keep the softening agent in place and also filters large particles from water.
- List five components of the zeolite regenerating system?
- Tank.
- Strainer.
- Brine injector (Venturi fitting).
- Dolt.
- Gravel.
- Trace the flow of water from the supply through the softener?
The hard water enters the multiport valve and is directed to the top of the softening tank. From the zeolite , the water is filtered and sent to the multiport valve, which then directs it to the building.
- How does the brine regenerate the zeolite?
The sodium ions in the salt replaces the magnesium and calcium particles collected by the zeolite.
- Give a brief description of the regeneration cycle for the water softening system ?
The brine is drawn out of the brine tank by the flow of hard water passing through the brine injector. It then flows through the multiport valve which direct the mixed solution to the bottom of the softening tank. It passes upward through the zeolite , back through the multiport valve , and then it washes to a drain.
- How is multiport valve set in the rinse position of water softening equipment?
It sends hard water through the tank to rinse away the brine.
- What determine when the softening agent needs regeneration or when regeneration is complete?
An automatic sensing device is installed in the piping.
- Will the discharge of the rinse water (brine) into septic tank affect its working conditions?
It may be safely discharged into a septic tank under normal working conditions but new tanks and those recently cleaned should be given ample time to become seeded.
- Why should precautions be taken for proper support of softening units?
For example the operating weight of a 2010BIS-3 unit by the manufacture’s specification sheet is 28,500 lb.
- Approximately, how many square feet of floor space would the 2010BIS-3 water softener unit require?
A = L1xW = 24’x6’-4” = 151.92 sq. ft.
- What is the minimum ceiling height for 2010BIS-3 water softener unit?
About 12’-4”.
- How can iron and manganese be removed from individual water supply?
- Small amounts can be removed in ordinary water softener.
2. Larger quantities can be removed by filtration.
- The three operational modes water softener control unit?
- Fully automatic.
- Semi-automatic.
- Manual.
- How can fully automatic operation of twin softeners be accomplished?
By adding a sequencing pilot and pressure switch in conjunction with a Bruner-Matic control center.
- Describe the operation of the automatic Capacity-Trol Brine Maker and flow controller on the Bruner Model HBR water softening unit?
- It combines salt storage and brine making in a single compact unit. An automatic brine valve is housed at the bottom of a brine well. It controls brine withdrawal and regulates fresh water refill.
- The flow controller automatically maintains proper backwash and cleansing flows over wide variations in operating pressures. Proper sizing and adjustment is done at the factory.
- What rye of treatment is used to remove gases such as hydrogen sulfide and carbon dioxide from individual water supply systems?
Adding a chemical such as chlorine that will convert the gas to a solid, and then filter the solid from the water.
- Who is qualified to make the necessary test on a water supply to determine what treatment is necessary?
A local testing agency take a sample of the water and have it analyzed.
- Why is hard water among the easiest water problems to spot?
It leave white, scaly deposits on plumbing fixtures and faucets, household appliances and kitchen equipment, produce streaky dishes, gray laundry and itchy skin.
- What are some colors of tap water which indicate the presence of hard or acidic water?
- Green or blue-green generally means overly acidic water.
- Yellow is the color of decaying vegetation.
- Red water suggests the presence of dissolved or precipitated iron .
- Black stains on fixtures and laundry indicate manganese.
- How can the damaging, corrosive effects of hard water be further reduced at the tap?
New faucets use ceramic disc cartridges in the place of plastic or metal parts.
- What is the best solution for removing most odor from potable water?
Special-purpose filters are the best prescription for most water odors.
- Describe the types of water filters which are the most common?
- Carbon filters. Tap water passes through activated carbon granules, which reduce organic materials, chlorine, dissolved gases and some minerals. Available as carafes, tap mounted and countertop appliances.
- Revers osmosis filters. A semi porous membrane reduces bacteria, lead, mercury, iron and most other contaminations. Installed under the kitchen sink.
- Distillers boil, condensate and filtered through a carbon filter water. Available in countertop models as larger, installed appliances.
- What steps should you take when taking a water sample?
- Secure a 16 oz. container that will not contaminate the sample. Clean, rubber-stoppered, resistant glass bottles or new plastic (baby) bottles are recommended.
- Before taking samples allow the water to run for at least five minutes.
- Rinse the container thoroughly with the water that is to be analyzed.
- Fill the bottle to a point just above the shoulder.
- Jot downfall pertinent information regarding the water.
- Send the sample in for the test.
- Pertinent information regarding the sample of the water?
- Source of the sample.
- Physical appearance (clean, dirty, highly colored, etc.).
- Odor.
- Taste.
- Number of persons in the family.
- The number of bathrooms in the home.
- The pump capacity in gph.
- What are some common complaints by owners of individual supply systems cause by water hardness due to calcium and magnesium?
- Soap and synthetic detergent wastage.
- Reduced life of washable fabrics.
- Poor laundering results.
- Poorer dish washing results.
- Lowered efficiently and fuel waste in water heaters.
- Poorer cooking results.
- Lack of cleanliness and sanitation in washing the skin, bathing, shampooing. Red, itchy or dry skin.
- What are some common complaints by owners of individual water supply caused by iron and manganese?
- Water is clear when drawn from faucet, but red rust appears upon standing.
- Water darkens coffee, tea, and other beverages.
- Rust stains on fabrics, plumbing fixtures, china, glassware and silverware.
- Water has metallic taste.
- Stains and deposits appear almost black when manganese is present.
- Complaints when hydrogen sulfide is present in individual water supply?
- Water has a rotten egg odor.
- Silverware tarnishes rapidly on contact with water.
- Yellow to black stains on plumbing fixtures and rusting of water systems.
- Darkens coffee, tea and other beverages.
- Ruins flavor and appearance of foods.
- Complaints caused by corrosive water (chiefly as result of oxygen and carbon dioxide content) in individual water supply?
- Premature failure of water heater and plumbing through leakage.
- Clogging of pipes due to corrosion tubercles.
- Rust stains on fabrics, plumbing fixtures, china, glassware and silverware.
- Blue stains on plumbing fixtures.
- Complaints caused by live organisms by decaying organic material in individual water supply?
Organic matter, microbiological organisms, or chlorophnols.
- Complaints caused by organic color in individual water supply due to presence of tannins and or humid materials?
- Yellow or brown colored water.
- Yellow or brown stains on washable fabrics, plumbing fixtures, utensils.
- Objectionable flavor and appearance of foods and beverages.
- Complaints caused by turbidity due to presence of fine particles of silt, mud, sand, etc. which are suspended in individual water supply?
- Cloudy, unpalatable appearance.
2. Deposits in valves and pipes.
- Complaints due to pathogenic organisms in individual water supply?
Water-borne disease (typhoid, amoebic or bacillary dysentery, epidemic jaundice and cholera).
- Complaints due to fluorides in individual water supply in excess of 1.5 parts per million?
Mottling of teeth.
- Complaints caused by nitrates in individual water supply?
Cyanosis (blueness of skin) and possible death of infants, especially under six months of age.
- Complaints due to excessive total dissolved solids in individual water supply. Laxative effect caused by excessive sulfate content of sodium and magnesium?
Brackish or saline water objectionable salty taste and laxative effect in some cases.
- Why does distribution systems ensure the delivery of potable water from the treatment plant to the consumer?
They are either public or private. Installation practices and protection of water mains and services are same for both. A private system generally means water supply restricted to a private home.
- Where is the biggest water treatment plant in USA?
In Chicago.
- Responsibility of EPA?
Make rules , standards, require publication to consumers.
- Daily usage of domestic water?
100 gal of water per person.
- What is meant by municipal potable water distribution systems?
All piping from the treatment plant to the consumer: main distribution lines, trunk lines, water mains and water see vices owned and operated by a governing body.
- Why is treatment of municipal sources of supply essential?
Sources of water have almost all become polluted and must be treated to produce water fit for human consumption.
- What are the function of main distribution lines and trunk lines?
Main distribution lines are the large water conduits that connect the treatment plant to smaller trunk lines, which further distribute the water to the mains of the system.
- What are the functions of water mains and water services?
Water main distribute water from trunk lines to the individual water services. Water services carry water from the mains directly into the building of the consumer.
- What are the function of water distribution systems?
Originally, distribution systems were installed primarily to furnish protection against fires. Today, fire protection has become secondary, and the primary function of distribution systems is to deliver potable water to the consumer.
- What are three types of water distribution systems?
- Loop system.
- Gridiron system.
- Tree system.
- What is loop system?
Large feeder mains surround many city blocks, and serve smaller cross-feed lines which are connected at each end into the main loop.
- What is gridiron system?
The piping is laid out in checkerboard fashion with piping usually decreasing in size as the distance increases from the source of supply.
- What is tree water distribution system?
There is a single trunk main, reducing in size with increasing distance from its source of supply; branch lines are supplied from the trunk.
- How is tree water distribution system more commonly called?
Dead-end system.
- Which water distribution system is most reliable?
The grid and loop systems provide better reliability because of their multiple paths. The grid is much more likely to permit uninterrupted service in the event of a breakdown in a part of the system, and continuous circulation helps to eliminate tastes and odors that can build up in a dead-end line.
- What is the general conception of a grid water distribution system?
- treatment plant.
- Closed reservoir.
- Trunk lines.
- Block by block water main grid.
- Pump station. Location differ from the system layout.
- Three different layouts of grid distribution systems?
- Water is pumped from treatment plant to a high, closed reservoir and delivered to water main grid by gravity.
- Pressurized system fed from a closed reservoir.
- A gravity system fed from a high tank that is, in turn, fed by pressure from a closed reservoir, that is fed by gravity from plant.
- What is the purpose of the multiple distribution layout of grid water supply system?
Continuous service is the purpose. In Oder to accomplish this , reserve capacity is necessary in the form of additional storage, pumping, and distribution facilities.
- How are the trunk lines and mains generally valves in a distribution system?
They are usually valves at each intersection (4 valves on cross intersection and 3 on T, one valve on each line).
- What are two common function of most pumping stations?
- Deliver water under pressure to higher elevation.
2. Introduce higher pressures into system.
- What are two type of pressurized water supply systems?
- In direct system water is pumped from the treatment plant to the distribution system.
- Indirect system use pump to deliver water to a closed reservoir or tank for distribution.
- Pumps for grid and loop water distribution system?
- Direct system use positive displacement pumps: reciprocating or rotary type.
- Indirect system use non-positive displacement pump of the centrifugal type.
- How do main distribution lines, trunk lines, and mains of water supply vary in size?
Main distribution lines generally are largest lines.
Trunk lines are usually smaller than the distribution lines.
Mains in most cases are smaller than the trunk lines.
Whenever possible, sizes are graduated to keep down the cost of installation and maintenance.
- List eight installation practices that can apply to all portions of any water distribution system?
- Safety procedures for excavating and shoring, handling pipe, making joints, and testing.
- Proper depth of burial.
- Proper bedding of pipe.
- Proper placement of rods and thrust blocks to prevent rupture to joints.
- Thorough testing to ensure against leakage or contamination.
- Protection to prevent corrosion.
- Care in backfilling.
- Chlorination of pipelines after installation to prevent pollution due to unsanitary conditions in the pipe.
- Why are safe work practices and procedures ignored in many cases?
Lack of experience, poor attitude or for reasons of supposed economy.
- What are some safety procedures to follow when working in a ditch (trench)?
They should be sloped or shored, or both. Ditches in crumbling or sandy soil should be solid sheeted.
Never work alone in a ditch. Be alert at all times; there is no such thing as a completely safe ditch.
- List five safe work practices which should be adhered to when handling or lifting heavy pipe with hoisting equipment?
- Be sure lifting cables and rigging equipment are in good working condition.
- To avoid confusion, have only one competent person giving signals and giving orders.
- Be alert at all times.
- Never work or stand under a hoisted load.
- Utilize proper rigging procedures.
- Why must pressurized water piping in a distribution system be thoroughly tested to guard against leakage and contamination?
The pressure on a dead-end or a fitting can develop into tons of thrust.. In the event of a failure, the resultant blowout can cause extensive damage and perhaps personal injury.
- Where should persons keep during the testing pressurized water piping in distribution system?
Clear of fittings and dead ends.
- How much thrust can develop at a dead-end during a hydrostatic test of a pipeline?
For example a 10” line being tested at 100 psig.
Tt = .7854xDxDxP =?.7854x10x10x100 = 7,854 lb ~ 3.5 ton.
All blocking or testing equipment must be capable of withstanding this amount of thrust.
- What is probably the earliest material known to have been used for water distribution systems?
Clay pipe.
- Materials for the main distribution lines?
Concrete, steel, and some types of plastic pipe.
- Materials for trunk lines and mains of water distribution systems?
Usually cast iron or ductile iron for ease of tapping for water services.
- Materials for water service piping?
Generally cast iron or ductile iron for the larger services; copper, brass, galvanized steel, and some types of plastic pipes are available for smaller services.
- Types of joints for concrete pipe?
Bell and spigot rubber gasket joints.
- Types of joints for steel pipe?
- Welded joints.
- Flanged joints.
- Mechanical joints.
- Types of joints for cast iron or ductile iron pipe?
- Push-on joints.
- Mechanical joints.
- Flanged joints.
- Caulked joints.
- What condition, other than poor or unstable soil, can cause a pipeline to settle?
Improper bedding (preparation of the ditch bottom) of a pipe line during installation.
- What does pipe installation include when the soil is poor or unstable?
Usually includes removal of the soil to a depth well below the desired pipe elevation. The ditch is then refilled with stable, compacted material such as bank run gravel.
- Which of the bedding methods for pipe installation is the most effective?
Contouring the ditch bottom to fit the pipe and then tamping the backfill.
- What is used in underground installations to prevent joints and fitting from coming apart (blowing out) when water pressure is applied to the line?
Pipe clamps sometimes called friction clamps and tie rods sometimes called rodding.
- How are pipe clamps and tie rods installed to prevent joints and fittings from coming apart when water pressure is applied to the underground water line?
- A pipe clamps are placed on either side of the joint and they are tied together by means of threaded rods that pass through the clamps on either side of the joint. Washer and nuts then secure the threaded rods.
- Two pipe clamps are placed on the pipe at angles f stress opposite to one another in front of the joint. Threaded rods are then inserted through the holes of the mechanical joint flanges at two locations. One rod connects to the first clamp and the other rod connects to the second clamp. The threaded rods and mechanical joint flanges are then secured by washers, nuts, and spacers.
- If mechanical joints are being used with rods, is it also always necessary to use clamps?
If section are to be subjected to very high pressure or if the pipe joints must be deflected slightly to follow ground contours, continuous rodding may be required
- How can continuous rodding be done without clamps?
Two rods run from flange to flange, using alternating bolt holes at each joint.
- List two methods of restraining joints water supply pipe that would eliminate continuous rodding?
- Each length of pipe can be back filled and compacted between joints on straight runs of underground piping installed horizontally prior to testing. The area around each joint or point of connection must be left exposed for visual inspection.
- Restraining devices are available for both push-on and mechanical joint piping installations.
- How is the entire pipeline often restrained for installations in poor soil or for critical lines?
With the FIElD LOK gasket and push-on joint ductile iron TYTON pipe or fitting the joints are restrained without thrust blocks, bolts, grooves, rods,clamps or retainer glands.
- List eleven steps which must be used in the assembly of a FIElD LOK gasket inside the bell socket of a section of ductile iron pipe?
- Loop the gasket for insertion.
- Make the loop between the locking segments to prevent damage to the rubber to metal bond.
- Place the gasket into the socket with the heel of the gasket in the retainer seat of the socket.
- Seat the gasket evenly around the inside of the socket with the heel of the gasket fitted snugly in the retainer seat and at or below the level of the throat of the bell socket.
- Apply a thin film of TYTON JOINT lubricant to the exposed surface of the gasket that will come into contact with the entering pipe spigot end.
- The outside of the cut end of pipe should be beveled about 1/4” at an angle of about 30* and the leading edge should be rounded with a coarse file or a portable grinder.
- Clean the last 6” or7” of the end of the pipe. Make an assembly mark infield cut pipe at a location in accordance with the pipe size.
- Apply a thin film of lubricant around the outside circumference of the spigot end for a distance of about 1”.
- Insert the end of the pipe into the socket until it contacts the gasket.
- Assemble the joint until the inside edge of the first painted stripe is flush with the bell face.
- Feeler gauge can be inserted into the socket to verify the proper installation of the joint.
- What is the purpose of TR FLEX GRIPPER rings?
To restrain field cut pipe (pipe without weld meant) inside ductile iron pipe and fittings.
- How are TR FLEX gaskets installed?
- clean the socket and the gasket.
- Loop the gasket and place it in the socket with the rounded bulb end entering first.
- Apply a thin film of TYTON JOINT lubricant to the exposed sur face of the gasket.
- What must be used where thrust blocking is not practicable?
Proper tie rodding.
- What are thrust blocks and where are they used?
Kick blocks are pads of concrete mix poured behind a fitting or a dead-end for the same reason that rods are used to prevent joints from blowing out.
- What is the concrete mix for the pads of thrust blocks?
Not leaner than 1 part cement 2 1/2 part sand, and 5 parts stone or gravel.
- Compute the size of the thrust block needed behind a 12” 90* elbow, in a buried pipeline 4” deep which contains water 90 psig.
A 12” 90* elbow develops 216 lb thrust at 1 psig of water pressure.
Tt = 90x216 = 19,440 pounds of horizontal thrust at 90 psig.
- How can contamination be caused by leakage?
In the event of negative pressure in an underground pipeline, contamination may enter through the leak or crack.
- How are potable water distribution system generally tested?
Hydrostatically at pressures equal to at least one and one half times the normal working pressure.
- Are all buried pipelines subject to damage from corrosion?
No. The extent of the damage depends on the soil and water conditions and types of piping materials. Metallic pipelines maybe subjected to corrosion. Plastic piping, although non-corrosive.
- What is cathodic protection?
Electrochemical process in which the metal to be protected is made the cathode in a galvanic cell.
- What are two methods of producing a cathodic protection effect?
- The impressed circuit process.
2. Use a sacrificial anode.
- How does impressed circuit process use an anode of less activity?
Connect the positive terminal of a source of direct current to scrap iron while the negative terminal is connected to the pipeline.
162 Trace the electric current in the cathodic protection system using a subcritical anode?
The magnesium becomes the sacrificial anode because it is more active than the pipeline. The positive electricity leaves magnesium, flows through the electrolyte ( soil) to the pipelines, and returns through the wire.
- How can contamination that occurs during construction be eliminated?
The pipelines should be flushed thoroughly and then disinfected by inserting liquid chlorine compound into the system. The pipeline is then filled slowly with water and the co cent ration of chlorine checked for disinfecting strength. The full line should be allowed to stand for at least 12 hours and then be thoroughly flushed with potable water.
164.How are water services generally classified?
As residential and commercial.
- What factors determine usually water service sizes?
- Type of use.
- Number of people using the water.
- Type of fixtures.
- Maximum demand at
peak use. - Pressure loss.
- Friction loss.
- How are services connected to mains?
- By installing a tee in the main .
2. By tapping a main and installing a valve.
- How is tapping done while a pipe is under pressure?
With the use of a yapping machine which strapped to the water main.
- What is the tapping machine used to?
Drill a hole in the main, tap the hole, and screw in the valve (usually called a corporation cock or stop).
- What is method of tapping water mains under pressure other then use of a tapping machine?
By strapping a saddle to the pipe. The valve is screwed into the saddle to make a water tight joint. A hole is drilled into the pipe through the valve.
- How can service connections larger then 2” be made under pressure?
By drilling through a valve that has been connected to the water main by means of a saddle or a split tapping sleeve (T).
- How is water service connected to small water main?
By manifold tapping - several smaller taps joined together by means if a yoke or fittings and then be connected to the service piping.
- Dice components of residential water service?
- Corporation cock or stop.
- Curb cock or stop.
- Curb box.
- Meter and meter yoke.
- Shutoff valve immediately inside
the structure being served.
- Installation practices for water services?
These practices include safety, bedding, protection and testing.
- Protection practices for water services?
Swing joint following a corporation stop.
A sleeve at point of entry to the structure.
- List some materials that are available for the installation of water services?
Cast iron, copper, brass, galvanized, and plastic.
- The types of water services pipe joints?
- For cast iron and ductile iron - mechanical, caulked, push-on, and flanged joints.
- For copper pipe - flared, sweat, flanged and braced joints.
- For brass pipe - screwed, braced and flanged joints.
- For galvanized pipe - screwed and flanged.
- For plastic pipe - bonded, welded, compression, solvent cement or clamped.
- How is the amount of payment for potable water computed?
By the local water purveyor, usually at a fixed rate for the number of gallons or cubic feet of water used.
- What are the most commonly used types of water meters?
- Positive displacement - register small amount of flow.
2. Turbine and compound are used for registering large flows.
- Two types of positive displacement meters?
- Positive displacement meters.
2. Oscillating-piston and nutating- disc meters.
- How do positive displacement meters operate?
As water passes through the chamber, the piston or disc makes one complete cycle. Each rotation is transmuted to a recording dial by means of a gear train.
- Where is a turbine meter generally used?
When a building requires large and constant volumes of flow with a minimum loss of line pressure.
- Describe the operation of a turbine meter?
Water entering the turbine meter is divided into two equal streams and passed through impellers. The rate of velocity is translated into gallons per minute by means of a series of gears connected to a recording dial.
- Where is compound meter usually installed?
In hospitals or apartment houses when rates of flow will vary greatly because of low and peak load periods.
- What is compound water meter?
It is a combination of a disc or oscillating piston meter and turbine meter. A compound valve closes off flow to turbine during low flow and to the disc portion during peak flow.
- How are meters incorporated into a water service?
By means of a special device or piping arrangement called a meter yoke.
- What is a meter yoke?
An arrangement of pipe and unions or flanges that will permit the meter to be removed without interruption of service.
- How is continuing service provided when the meter is removed?
A pipe nipple with washers can be installed in its place.
- Name of meter couplings?
Yokes.
- Where have large meter assembly be contained outside building?
In a meter vault.
- What are the primary reasons for selecting a manifold or flexible battery installation?
Lower weight and cost and greater ease of installation in a large service (8” and lager).
- What are some problems encountered in installing large meters?
No extra space can be built into the meter assembly. The only extra space available is the thickness of two extra gaskets (about 1/4”).
- What types of water meter utilize the magnetic drive principle?
Disc meters, oscillating piston meters, turbine meters, turbo meters, single register compound meters.
- Explain how water meter with the magnetic drive operates?
Rotation of a spindle drive magnet. It transmit rotation through the wall of a meter to a second magnet which operates the meter register.
- Parts of disc meter?
- Chamber.
- Disc.
- Spindle.
- Chamber magnet.
- Second magnet.
- Register.
- Parts of oscillating piston meters?
- A bronze case.
- A sealed register.
- Heat-treated glass.
- Piston type measuring chamber.
- A oscillating piston.
- Permanent magnets.
- A magnetic coupling.
- Follower magnet.
- Register reduction gearing.
- A cylindrical strainer.
- A built-in register retainer.
- An interchangeable bottom plate.
- Parts of turbine meters?
- Housing - cast iron.
- Cover - bronze.
- Nuts - bronze.
- Test plug - bronze.
- Screen - bronze.
- Turbine cage - bronze.
- Spindle - stainless steel.
- Turbine wheels - hard rubber.
- Bushing - hard rubber.
- Adjustable bearing - agate.
- Parts of turbo meters?
- A rotor.
- Magnetic coupling.
- A vertical spindle.
- Gears.
- The meter’s register.
- Straightening vanes.
- A nose cone.
- Parts of single register compound meters?
- A single hermetically sealed totalizer.
- Magnetic couplings.
- A measuring chambers.
- A reduction gear trains.
- Turbine chamber.
- A positive displacement (bypass) measuring chamber.
- A swing action valve .
- Why is goose neck usually installed conterclockvice?
For protection against breakage because curb valve is usually shut off conterclockvice.
- Parts of municipal water distribution system?
- Main distribution lines.
- Trunk lines.
- Water mains.
- Water service.
- What is a building water supply system?
The piping within a building which conveys water from the water service pipe to the point of use .
- What are five characteristics of a quality installation?
- Provides an adequate supply of water.
- Provides necessary safeguard to protect the system from contamination from both inside and out side the building.
- Maintains suitable pressure for usage demands in the building.
- Is quiet and relatively maintenance free.
- Supplies adequate amounts of water to the hot water generation system.
- What are three basic terms associated with making and installing plumbing system?
- Design.
- Layout.
- Installation.
- Why is it important, in your study of plumbing systems, to become familiar with design, layout and installation?
Success will depend on how well the basic principles are understood and applied to meet the needs of a particular job.
- Why can’t the elements of design, layout, and installation be easily separated and clearly defined in some industries and occupations?
Because of wide variations in responsibilities: a very carefully designed system to install, including drawing and specifications, or no information other than location of plumbing fixtures.
- What are two steps in design of the water supply systems?
- The architect allocates the space or location of its components.
- A mechanical or civil engineer does the actual piping arrangement.
- List same specific knowledge a journeyworker might need to design a building water supply system?
- Customer specifications, piping materials, joining techniques, support, insulation.
- Code requirements.
- Locations of components of the system.
- Equipment size and pipe size requirements.
- List some general knowledge a journeyworker might need to design a building water supply system?
- What is to be done and how it will be accomplished.
- Math formulas.
- Joining and support techniques.
- How to sketch the system and its components.
- Material characteristics.
- Safety requirements.
- Where would the water meter be located, if the water service pipe is from a public source?
Most individual water meters are located out side the building for accessibility. In some cases meter are located inside the building. You might also be required to install a back flow preventer in conjunction with the meter to protect the community water supply system from contamination.
- What are the major parts of a building water supply system?
- Mains.
- Mains branch lines.
- Risers.
- Minor branch lines.
- Terminal points.
- Describe the function of a main distribution line in a building water supllly system.
Convey the water to major branches and risers.
- Describe the function of a major branches?
Carry the water from the distribution mains to special equipment, minor branches, and risers.
- Describe the function of raisers in a building water supply system?
Transport water vertically at least the hight of one story ( one floor to another). Risers are supplied either by the main distribution line or a major branch. And they, in turn, supply either a major or minor branch line on a different foor.
- What is the function of a minor branch Ina building water supply system?
Conveys the water from major branch lines or risers to the point of use called a terminal point.
- Are drawing and written instructions or specifications always necessary for designing plumbing systems?
No. Residential and remodeling work are examples of plumbing systems designed by a journeyworker, in a whole or in a part, without drawings or specifications. The basic elements of design are done mentally.
- What does the term layout mean?
Locate the various parts of system.
- What parts of water supply system are not shown on the drawings but are critical to the operation and maintenance and are described in the specifications?
Branch valves, unions, strainers, pressure Gage’s, thermometers, and drain valves.
- List some of the specific information which is usually required to lay out a building water supply system?
- Pipe size to be used.
- Kinds of pipe or tube materials to be used.
- Location of mains, risers, and branches.
- Location and types of sleeves, inserts, hangers, and supports.
- Types, sizes, and location of fixtures and equipment.
- Location of hangers, supports, and pipe connections to fixtures and equipment.
- Following an analysis of the general principles of design and layout, list some of the steps that are important in the installation of plumbing systems?
- Select an area for storing pipe, fittings, etc. on the job.
- Select an area for pipe cutting and assembly, and set up of equipment.
- Determine the most logical procedure from design and layout information, such as pre assembly of parts and order of installation.
- Make working drawing s or sketches when necessary.
- Determine required pipe and fitting sizes.
- What are four terms closely associated with the design of building water supply systems?
- Friction.
- Velocity.
- Rate of flow.
- Pressure.
- Define the term friction as it applies to a building water supply system?
The water that is in contact with the walls of the pipeline moves at a lower velocity than the water in the center of the pipeline. The result of friction on flow is measured as pressure loss.
- Define the term velocity as it applies to a building water supply system?
The rate at which liquids move through a piping system, measured in feet per second.
- Define the term rate of flow as it applies to a building water supply system?
The volume of a moving fluid related to time. It is measured in gpm, gph, mgd (millions of gallon per day), cfs, cfm, cfd.
- Define the term pressure as it applies to a building water supply system?
Force acting on a surface. It is usually measured in pounds per square inch psig.
- What causes pressure variation at any given point in a building water supply system?
- Rate of use.
- Fluctuation of pressure in the main due to rate of use by other customers.
- Changes in pumping head.
- Changes in elevation head.
- Friction of water.
- What term is normally used to designate pressure drop due to elevation?
It can be referred to as head loss.
- How much head pressure is exerted by a column of water 1’ high?
A column of water 1’ high is equal to .433 psig.
- How much pressure is exerted on the upper gage if pressure at bottom gage is 50 psig and elevation is 14’?
Head pressure is 14x.433=6.06 psig.
The pressure on the upper gage :
P1-HP=50-6.06=43.94 psig.
- If the upper gage indicated a pressure of 50 psig, and the head pressure 6.06 psig, would the lower gage indicate 56.06psig?
Yes, the head pressure would be added to the upper gage pressure.
- How is pressure per square inch at the base affected by the shape if a container?
Neither the shape of a container, nor the area of its base affects the pressure (static) exerted by a column of water. The vertical height of the column is the factor that must be used.
- What happens if the pressure in a water pipe becomes less than atmospheric and a faucet is opened?
Air flows into the faucet and forces the water ahead of it toward the point of lower pressure. If the faucet opening is submerged at the time of the negative pressure the result is back siphonage.
- Is the pressure in a water supply system the only factor that determines the velocity of the water within a pipeline?
No. Pressure forces the water through the pipelines, but only that fast as that water is used. Velocity in a water supply system is the result of demand at the point of use, capacity of the supply system, and pressure.
- Fill a five gallon pail from a faucet connected directly to a pipe or tube with a 1/2” inside diameter (I.D.). Open the faucet fully, it take one minute to fill the pail. What is the flow rate in gallons per minute and cubic feet per minute?
FR = TF(volume)/T(time) = 5/1 = 5 gpm = 5/7.48 ~ 5/ 7.5 = .67 cfm.
- Five gallons of water moved through the pipe while the pail was being filled. How many cubic inches of water does this represent?
One gallon of water contains 231 cubic inches , therefore:
231x 5 = 1155 cu. in.
- Determine the volume of water moving through the pipe in cubic inches per second if 1155 cu. in, move per 1 minute?
V(volume) = 1155/60 = 19.25 cu. in. per sec.
- Determine the velocity of water in feet per second (fps) if volume of water is 19.25 cu. in. per sec. and pipe has 1/2” inside diameter?
V = Vol/ A , where V - velocity,
Vol - volume,
A - area, A = .7854xDxD = .7854x1/2x1/2 = .196 = .2 sq. in.
V = 19.25/ .2 = 8.02 fps.
- What are generally accepted rates of flow within building water supply pipelines?
The rate suggested for general service water is from 5 to10 fps. Velocities above the maximum may cause interior erosion of the piping, noise and vibration, below the minimum may cause stagnation of the water.
- . If a faucet on the second floor, 8 feet higher than the first one and the flow was measured at the point with the faucet wide open, would it take longer to fill the pail?
Yes, because
- The pressure is less at the higher elevation,
- Pressure is lost in the friction of the longer pipe run.
- List six design considerations taken into account when sizing large or small water supply systems?
- The available pressure from the water main.
- Minimum and maximum pressures required at the fixtures.
- Static pressure losses. (Head).
- Individual and total fixtures dim and in gpm.
- Flowing pressure (friction) losses.
- Velocity limits.
- Determine the demand (including hot water) for each of the fixtures a typical residence and total demand?
- Water closet 3 gpm.
- Lavatory 3 gpm.
- Bathtub 6 gpm.
- Kitchen sink 4.5 gpm.
- Laundry tub 5 gpm.
Total demand 21.5 gpm.
- Does the water service pipe for the residence need to be sized for a demand of all fixtures of it?
No. The fixtures in a residence are not subject to continuous use. These fixtures are rated as intermittent use fixtures. Most codes have a minimum size service pipe which may take precedence over actual demand.
- What is meant by continuous flow to a water-using device?
For extended period of time, as compared with most plumbing fixtures, water flows to or through the device at a constant rate of flow.
242 Examples of continuous flow to a water-using devices?
- Lawn sprinkling systems.
- Cooling water for refrigeration and air conditioning compressors.
- Many type of industrial equipment.
- Decorative displays.
- Swimming pool filters.
- Sill cocks.
- What does simultaneous use mean?
A number of devices demanding water are in use at the same time.
- What is meant by the term demand weight?
The number of water supply fixture units (WSFU) of the fixture as compared to the flow of water to a lavatory which is assigned a value of 1 WSFU.
- How long must the drainage pipe from the water closet be able to handle the removal of the entire contents of the closet?
From 6 to 11 seconds.
- What are WSFU and FU ?
- Water supply fixture units.
2. Fixture unit used for drainage.
- How are the WSFU in tables used in determining pipe sizes?
The procedure used to determine the WSFU for each branch (H and C) is to rate each branch as demanding 3/4 of the WSFU assigned in the table. It help determine the size of water supply piping as well as water service pipelines when the demand weights of the various fixtures can be totaled and then converted to gpm.
- Why is it better to use a 30-60-90* clear plastic draftsman’s triangle with a straight line parallel to the short side than a straightedge or ruler?
The clear triangle, with its vertical and horizontal edges, enables the user to read the values at the edges of the graph without moving the device, and also read along the parallel line of the triangle to an intersection point on the graph.
- List the fixtures and their value and determine the total demand units from table for a public building that have the following fixtures installed: 4 lavatories, 1 drinking fountain, 5 water closets (flush valve), 3 urinal, siphon jet, wall-hang (flush valve), 1 janitor’s service sink?
Make separate list for the cold and hot water:: CW: 5 WC,FV 5x10 = 50 WSFU, 3 UR, FV 3x5 = 15WSFU, 4 L 3/4x(4x2) = 6 WSFU, 1 JSS 3/4x(1x4) = 3 WSFU, 1 DF 1x1 = 1, Total demand 75 WSFU. HW: 4 L 3/4x(4x2) = 6 WSFU, 1 JSS 3/4x(1x4) = 3 WSFU, Total demand 9 WSFU.
- Convert WSFU to gpm for determining pipe size if CW system has 75 WSfU and flush valve WC, HW system has 9 WSFU?
Use curve 1 of a graph if water closets are predominantly flush solves or curve 2 if they are tank type. The total demand of the 75 WSFU will be about 60 gpm. HW demand will be used to size the branch to the Water Heater and must be added to the total building demand. That CW demand for water heater branch 9 WSFU equals approximately 8 gpm. Total demand for building 50+8 = 68 gpm.
- Compute the total CW gpm demand for building that has 60 gpm fixtures demand, 8 gpm water heater branch, an air conditioning compressor that requires 21 gpm and sill cock?
Both the compressor and the sill cock are continuous flow devices . Each gpm they use is added to the total gpm calculated for the fixtures. Table shows that 1 sill cock with 50’ of hose equals 5 gpm. So the total cold water demand on the system is 8+5+21+60 = 94 gpm.
- What is generally considered to be “private” use for bathrooms, toilet rooms, or kitchens?
All bathrooms in private homes, apartments, hotels or motels rooms, and those for the convenience of an individual and his or her visitors in an office.
- What is generally considered to be “public” use?
All uses for public. It includes all places where the public is served food or drink employee toilet rooms in all commercial, industrial, and institutional building, lobbies of buildings, places of recreation, passenger stations, automobile service stations, airports, public convenience stations, public parks, rest rooms, etc.
- How is water supply demand determined based on use in a public or private situation?
1st curve is used for public and 2nd for privet use in the graph of probable water supply demand (gpm). This curves have been developed from mathematical probability equations.
- Hydrostatic test by NYC code?
50 psi above normal working pressure but not less than 150 psi.
- The minimum diameter of water service pipe by NYC code?
1”.
- Separation of water service and building sewer by NYC code?
By 5’ of undisturbed or compacted earth.
- Where can the water service pipe be within 5’ of the sewer by NYC code?
A minimum of 12” above the top of the highest point of the sewer and the adequate pipe materials.
- How shall water service cross a sewer pipe within 5’ by NYC code?
The water service pipe is sleeved to at least 5’ horizontally from the sewer pipe centerline on both sides of such crossing.
- Location water service near sources of pollution by NYC code?
It shall not be located in, under or above cesspools, septic tanks, septic tank drainage fields or seepage pits and shall be separated by a minimum of 10’.
- Types of flow charts of water supply system?
- Smooth copper pipe and tube - K, L, M copper and glass, plastic pipes.
- Fairly smooth pipe - new galvanized or steel pipe.
- Fairly rough pipe - new cast iron and used galvanized steel piping up to 10 years old.
- Rough pipe - old cast iron and steel water pipe.
- What values are expressed by the lines on the flow charts?
- The vertical lines on the flow chart represent the friction loss in head, measured in pounds per square inch gage per 100’ of length.
- The lines which run diagonally from lower left to upper right represent the nominal inside diameter of the pipe.
- The lines which run from lower right to upper left, represent the velocity in fps.
- The horizontal lines represent flow in gpm.
- Friction loss formula?
FL = PxL/100: FL- friction loss, P-pressure in psig, L-the length of pipe in feet, 100- hundred feet.
- Determine the pressure loss due to friction in a 20’-0” length of 1” diameter type M copper tube. with a 20 gpm flow rate?
9 psig is the friction loss by chart for 100’ of pipe. For 20’ it will be:
9/5= 1.8 psig.
- What is the velocity in feet per second for the 1” diameter line and flow rate 20 gpm?
Approximately 7.75 ft. per second.
- Calculate the minimum size of pipe that can be run to carry 40 gallons a minute, and the pressure loss cannot be more than 15 psig , the velocity must not exceed 12’ per second, and the length of the pipe is 100’.
Using table find the point at which 15 psig and 40 gpm intersect.this point is just above 10 fps, so it is within the velocity limits. That point is just below the 1 1/4” line, so 1 1/4” copper pipe must be used.
- How can you account for friction loss caused by the installation of fittings?
A liner value (length in feet) is assigned to each fitting, which is then added to the length of the pipe run.
- Account following fittings and valves in a straight 25’ section of 1” tube: 3-90* elbows, 2-45* elbows, 1-tube, 1-gate valve?
Fitting friction loss: 3-90* elbows: 3x1.5=4.5' 2-45* elbows: 2x1.0=2.0' 1-Tee: 0.45=0.45' 1-Gate valve: .3' All together: 7.25' Section of pipe run: 25'. Friction loss: 7.25+25.00=32.25'. Pressure loss for the flow of 25 gpm 1" line is approximately 13 psig per 100' of pipe run. The pressure loss for our section will be: 32.25/100x13 = 4.19 psig.
- How is the residual pressure measured?
The flow pressure is measured on the inlet side of the wide open faucet (upstream).
- What is minimum recommended pressure required to all lavatory faucets?
The minimum residual pressure is 8 psig.
- Comparison of static pressure to residual pressure?
Static pressure (no flow) ~ residual pressure (flowing) x 2.
- List four methods of supplying tall buildings with an adequate amount of water?
- Roof tanks.
- Hydro pneumatic tanks.
- Multistage pumps.
- Variable speed pumps.
- What must be the minimum elevation of the water line in the roof tank above the highest fixture outlet in order to supply the fixture?
H = P/P1ft = 8/0.433 = 18.5’.
If water closets with flush valves are used:
H = 15/0.433 = 34.6’.
Add the pressure losses due to friction for pipe, fittings, and valves and the outlet losses from the tank.
- What controls the pump that supplies water to the roof tank?
When the water level in the tank drops to a predetermined level, a control (either a float assembly or water sensitive switch) activates the pump to re supply the tank.
Another switch located just below the tank overflow, shut off the power to the pump.
- Define fire standpipe?
A vertical pipe that runs from the lowest floor of a building to above the roof and feeds water to fire hose cabinets, fire hose outlets, and fire sprinkler systems within the building or on its roof.
- O.S.&Y ?
An outside screw and yoke valve.
- What is a Siamese connection?
A double fire hose connection that is installed on the outside of a building. It is used by the fire department to pump or supply water to fire protection systems inside of a building.
- What may the fire department connect to a Siamese connection?
- Horses leading to street fire hydrants.
2. Hoses to fire pumping apparatus.
- Do fire pump era use sources of water other than from fire hydrants?
Yes. Suction houses from fire pumpers may also draw water from rivers, lakes, ponds, irrigation ditches, etc.
- How can the building water supply be protected from contaminated water of fire stand pipe?
- An elevated roof tank completely separated from the domestic water system.
- A reduced pressure zone back flow preventer can be placed in the location of the crack valve on the down feed domestic supply from the tank.
- Why are there several fire hose valves installed on the roof manifold?
Firefighters may connect hoses to fight a roof fire regardless of its location.
- What is hydro pneumatic tank?
A vessel which contains approximately two-thirds water and one-third air.
- How is the pressure controlled within the hydro pneumatic tank?
Pressure is sensed by the switches in the control panel through the small pipeline that is run from top of tank. When the desired pressure is reached, normally 60 to 80 psig, the pressure switch opens and shuts off the pump. At a minimum pressure, normally between 30 to 50 psig, the pressure switch activates the pump.
- How is fire protection provided in a hydro pneumatic system?
The fire standpipes can be fed from the pipeline serving the fixtures.
- How does a Multi-pump system work?
The smaller pump is capable of supplying minimum demands. If the demand is too great for the small pump, the pressure will continue to drop until the controller activates the larger pump to compensate for the pressure loss.
- How does Multi-pump system work?
Pressure-sensitive switches control the amount of power delivered to the motor. As the pressure drops due to increased demand, the next switch calls for more power. When this increased power is delivered to the motor, the speed of the motor increases and more head pressure from the pump is delivered to the system.
- List three types of nous in the pipelines of a water supply system?
- Water hammer.
- Vibration.
- Rushing noises.
- What is water hammer?
The shock, and accompanying banging noise, created when a valve or faucet is suddenly closed against water flow. It is caused by the abrupt alteration in the flowing of the water. The shock bounces back and forth along the pipe and may reverse itself several times from a single quick stoppage of flow.
- What can damage be done by water hammer?
Loosen pipe hangers, damaged parts of valves, faucets, or the water meter, loosen pipe joints or burst the piping. Any ordinary pressure gage can be ruined by water hammer.
- Is there any way to deal with water hammer?
- Mechanical shock absorbers in appropriate locations in the system.
- Adequately sized air chambers at the top of all risers each branch feeding groups of fixtures or equipment .
- Provide both mechanical devices and air chambers.
290.how does a mechanical shock absorber eliminate water hammer?
The shock and reversed flow are absorbed by an expandable bellows or a heavy- duty flexible tube (installed inside a protection metal cap).
- Where is shock relief needed?
All types of solenoid valves, spring -action faucets, self-closing faucets, icily-closing gate valves, and high-speed motor-operated valves.
- How does an air chamber prevent water hammer?
The air trapped in the upper part of an air chamber is compressed by the shock wave of water hammer and absorbs the kinetic energy of the shock wave.
- How does an air chamber is installed?
On horizontal piping, it is connected by means of a side outlet tee, on risers and water supply branches, it is installed at the top.
- Parts of rechargeable shock absorber?
- Gate valve.
- Petcock at base.
- Petcock at cap.
- How should an air chamber be sized?
- Not less in diameter than the pipe supply line served.
- Not less than 18” in length.
- If it is close to a quick-closing valve, the air chamber body should be at least one pipe size larger than the pipe served and its length should be increased by 18*.
- The connecting nipples and the shutoff valve should be not less than one-half the diameter of the supply pipe.
- How can noise caused by pipe movement through hangers and other supports be avoided?
By using hangers and anchors that are installed or covered with rubber, plastic, or other sound-deadening materials.
If the noise is caused by movement of pipe against a structural member, such as a joist, wall, or column, insulation should be placed between the pipe and the structural member.
- What is cavitation?
The condition that develops in fittings, valves, and at sudden enlargements when water at high velocity makes an abrupt change in direction.
- How can you reduce velocity and maintain rate of flow?
- Increasing the pipe size.
- Using fewer fittings.
- Using reducers instead of bushings.
- Changing the type of valve for better quality.
- How is the selection of the piping materials to be used in a building water supply system governed by?
- Specific use.
- State, local or provincial code requirements.
- Chemistry of the water.
- Amount of money to the spent.
- How does water chemistry affect pipe material selection?
The water contain different minerals and dissolved gases. The gases can make the water corrosive or the minerals can build up on metal surfaces. Treating the water supply, selecting materials that resist oxidation, using corrosion resistant glazes or linings and using a sacrificial element are methods used to slow down the corrosion process.
- What must the journeyworker know about design a water supply system for building?
- Where the service enter the building .
- Where pipe spaces, pipe chases, and partitions are located.
- Where pipe is to run above ceilings and how much space are available.
- Where other mechanical work is to be located.
- What types of drawing allow you to visualize the completed system?
A riser diagram or an isometric drawing.
- How do you select an area for material storage?
- Consider accessibility to unloading and assembly areas.
- Select a site out of the way of job progress.
- Discuss your selected site with the job superintendent for unknown problems or other plans for the area.
- List four factors which should be considered when selecting an area for pipe cutting and assembly?
- A power source.
- Nearness to the storage area.
- Protection from weather.
- Enough space.
- What are some factors which must be considered for preassembled?
- The assembly should have some degree of flexibility (one field cut measurement is an example).
- The final weight of the assembly must be considered. Will special equipment be necessary to transport and install the assembly?
If so, is this practical? - Typical assemblies, several of the same type should:
A. Be made on jigs for uniformity;
B. Have frequent checks for accuracy of measurement and quality of workmanship;
C. Be considered in the event they present storage problems.
D. Have one assembly completed and installed before continuing with production.
- How will the type of material used in a water supply system determine support requirements?
Most installations which require pipe covering also require that the hangers be of sufficient size to allow the covering to pass through the hanger.
- What type of identification shall the journeyworker provide for valves?
- Place numbered tags on all valves.
- A valve chart giving the number and location of each valve is another requirement.
- Provide and locate access panels for valves.
- Testing of a building water supply system?
A hydrostatic test or an air test is usually made.
- How are air test made on building supply systems?
The source of air pressure can be from an air compressor or from a cylinder of compressed air. If compressed air is used, be sure to use a pressure regulator in the tank.
- What can be done to ensure that the materials and tools are available when needed during the installation of a building water supply system?
Be sure you have planned ahead and have the tools and materials available.
After receiving them:
1. Provide adequate locked storage.
2. Keep storage area and stock in order.
3. Bag fittings for individual projects where practical.
4. Remind yourself that other tradesmen are usually required to buy their own tools and are more likely to borrow or steal yours.
5. Keep in mind that the tools and materials provided by the employer are not yours to give or loan, but do belong to the employer.
- What is hot water?
Hot water is water to which heat energy has been added, as more heat is added, the water becomes hotter.
- List some of the benefits of modern automatic domestic hot water systems?
- Better health, through the greater cleaning and sanitizing power of hot water.
- Safety, because hot water temperature can be thermostatically controlled, unsafe water temperatures also can be controlled.
- Convenience, because hot water at the desired temperature is always available.
- Utility, as much of the work requiring water is generally accomplished more quickly with hot water.
- Comfort, because heated water is easier to work with.
- Pleasure, increased with heated swimming pools.
- Leisure time, made possible by automatic clothiers-washers and dishwashers using hot water.
- Therapeutic effects, as warm water and circulation promote healing.
- What is the function of a hot water supply system?
Provide consumers with adequate hot water to meet their needs, at a predetermined temperature, as economically as possible.
- What effect does heat have on water?
It expands and circulates.
It can be converted from a liquid to a vapor.
- How does increase of volume of heated water relate to hot water storage heaters?
In water heater a volume of water increase approximately 1.7%. For 60 gallon WH it give 1 additional gallon of water.
- What causes static pressure in a hot water heater?
The physical weight of the water in the system above the heater.
- How can you find the static pressure to fill the water supply system to the top?
The height of the system divided by 2.31 (head pressure equal to 1 psi).
- What safety measures are usually taken to guard against the hazards caused by excessive expansion of water in a domestic hot water system?
A combination temperature and pressure (T&P) relief valve be installed at the heat source.
- How does a T&P relief valve work?
In the event the pressure portion of the valve fails, when the water reaches a predetermined temperature, the temperature portion of the valve takes over and discharges overheated hot water.
- What is the rate of expansion of water for each degree of temperature rise?
Water expands at the rate of approximately .00023% for each degree of temperature rise.
- Why does thermal expansion occur in a piping system every time a water heater comes on to recover the temperature lost through usage of hot water?
The greater the draw on the hot water the lower the temperature in the tank drops. The thermostat kicks the burner on and the temperature recovery is under way. The normal setting on the dial of the hot water heater termostat will give you approximately 140*F water.
- What happens when thermal expansion occurs in any hot water system if the water is heated o “recovered” during periods of non-use and the system is operated In an “open” condition or connected directly to the city main?
The volume of expanded water generated during water recovery periods can be dissipated back through the “open” conection to the city main.
- What happens when a back flow preventer or pressure reducing valve is installed in the cold water supply line to a hot water heater?
During periods of temperature recovery and no usage, expanded water has no place to go, so the reassure builds until a relief valve pops, spilling hot water.
- What causes a “non-return barrier” in domestic hot water systems?
Pressure reducing valves and back flow prevention devices in domestic water systems result a non-return barrier between the building water supply and the public water supply to protect municipal water supplies.
- How does thermal expansion cause dangerous increases in pressure in domestic hot water systems?
As water is heated it immediately starts to expand. In a piping system constructed of fairly rigid materials the water in it is confined to a practically fixed area, even though there might be a slight increase of space within the system due to expansion.
- When will a thermal expansion occur in residential usage?
Both in daytime and nighttime periods.
- What are some of the problems which are a direct result of thermal expansion?
Pressure increases resulting from thermal expansion, occurring frequently and repeatedly on a daily basis, produces dangerous stress and strain on hot water system piping and components. It can rupture pipe fittings that have been weakened by corrosion, collapse the center flues of gas-fired water heaters,. Rust-deteriorated tank surfaces can also be ruptured. Can cause malfunction of recirculating pumps, resulting in short-cycling and eventual pump burn-out.
Failure of critical components in water use devices, such as solenoid valves and “O-ring” seals in washing machines and dishwashers.
- What is a method which can be used as a solution to thermal expansion to control pressure increases within safe limits in a closed piping system?
An expansion tank with an air cushion, suitably lined to handle aggressive potable water. An expansion tank can have a diaphragm or bladder to separate the air cushion from system water will prevent loss of air through absorption by water.
- How do you lay service pipe (good neck) at connection to main?
To the right of pipe.
- What is back flow?
The undesirable reversal of flow in a potable water distribution as a result of a cross connection.
- Two types of backflow?
- Back siphonage.
2. Back pressure.
- Three types of backflow devices?
- Double check valve.
- Reduced pressure zone.
- Air gap.
- Three degrees of backflow and devices to eliminate it?
- No hazardous - non devices needed.
- Hazardous - air gap, RPZ.
- Aesthetically - double check valves.
- SDWA ?
The safe drinking water act.
- When was SDWA originally passed by congress?
1974.
- What does back siphonage mean?
The backflow of contaminated or polluted water, or water of questionable quality from a plumbing fixture or other customer sources, into a public water supply system main due to a temporary negative or sub-atmospheric pressure within the public water supply system.j
- What does backflow means?
A flow condition, induced by a differential in pressure, that causes the flow of water or other liquids and or gases into the distribution pipes of a public water supply from any source other than its intended source.
- What does back pressure mean?
The resulting backflow of contamination, polluted, or otherwise unacceptable quality water from a plumbing fixture or other customer sources into a public water supply system due to a greater pressure within the customer’s water system.
- Double check valve assembly components?
- Test cock # 1.
- Shutoff valve # 1.
- Test cock # 2.
- Check valve # 1.
- Test cock # 3.
- Check valve # 4.
- Shutoff valve # 2.
- What pressure must be held in the direction of flow by each check valve in double check valve assembly?
At least 1 psi.
- RP components?
- Test cock # 1.
- Shutoff valve # 1.
- Test cock # 2.
- Check valve # 1.
- Differential pressure relief valve.
- Test cock # 3.
- Check valve # 2.
- Test cock # 4.
- Shutoff valve # 2.
- What is the spring loading in the check valves of RP backflowpreventor?
- The fist will support pressures in the direction of flow of approximately 5-10 psi.
- The second must maintain a 1 psi.
- What is the best solution to thermal expansion?
Control the pressure it generates within a normal, safe operating range, well below the emergency setting of a relief valve.
- How can pressure be controlled in a domestic hot water heating system?
.1. A properly sized thermal expansion tank for use with domestic hot water heaters on the supply side of the water heater.
2. Using a combination ballcock and relief valve that limit the domestic water system preset static pressure to 80 psig.
- What is the major difference between a thermal expansion tank on the “closed” domestic hot water loop and a conventional diagram expansion tank found on a hot water space heating system?
The addition of a separate rigid, polypropylene liner on the water side of diaphragm. This allows the acceptance of potable fresh water in the expansion tank without corrosion taking place.
- What is the principle of operation and application of a thermal expansion tank?
The utilization of a sealed -in air volume under specific pressurization equal to the minimum cold water supply line pressure at the water heater to accommodate expanded water generated in the water heater during recovery periods.
- The following four operating characteristics of the service/domestic hot water system?
- The supply line or minimum pressure at the expansion tank location. ( Tank locations are customary on the supply side of the water heater).
- The desired maximum pressure to be allowed at the water heater.
- The operating temperature range of the water heater or hot water generator during its recovery period.
- Volume of water in the water heater or storage tank.
- Explain use of a thermal expansion tank as a solution for handling thermal expansion problems utilizes a calculated volume of air in a small pressure vessel attached to the hot water system?
Expanded water resulting from thermal expansion can enter the tank, compressing the air cushion to create the space it requires. Since the pressure in he air cushion is inversely proportional to the volume, pressure increase can be controlled within desired limits, by correctly sizing the air cushion volume through the application of Boyle’s Law for perfect gases.
- What are six components of the thermal expansion tank ?
- Acceptance fitting.
- Separate rigid polypropylene-lined water reservoir (NSF listed).
- Heavy duty butyl diaphragm.
- Sealed-in permanent air charge.
- Welded steel pressure support domes.
- Air charging valve.
- What is the definition of “specific heat” as applied to water which, is to be heated?
The amount of heat required to raise the temperature if 1 lb of water 1*F.
- Weight of 1 gallon of water?
8.33 lbs.
- What is the formula for determining the Btu required to heat a given quantity of water?
H = Wx^T, where
H- heat in Btu;
W- weight in lbs;
^T- temperature rise in degrees F.
- Efficiency of hot water heaters?
- Gas water heater - 70%.
2. Coil and tube water heater - 80%.
- How are the required Btu related to the gas input and efficiency of a gas hot water heater?
GI = H/HE = H/.7, where
GI - gas input in Btu;
H - heat in Btu;
HE - heat efficiency.
- What is it mean when it is estimated that 70% of the contents of a hot water storage tank are available at the desired temperature?
It is the amount of water available and has nothing to do with Efficiency. When hot water is drawn from the tank , cold water enters the tank and mixes with the water in the lower 30% of the tank.
- How many gallons of water per hour and each hour for 4 hours, is available from the heater at 140*F and recovery of 100 gallons per hour and with 100 gallon storage tank?
1 hour peak period: R+TC, where R - recovery = 100 gallons, TC - storage tank contribution = 70 gallons; 100+70 = 170 gallons per hour. 4 hour peak period: TC = 70/4 = 17.5 gallons, 100+17.5 = 117.5 gallons per hour.
- Two different methods that can be used when heating domestic hot water?
Direct heating and indirect heating.
- How does a direct water heater work?
The source of heat (gas, oil, or electricity) is located where the water is heated.
- How does indirect water heater work?
Water is heated by a heat source that is remotely located from the water heating equipment.
- How does indirect water heaters are classified?
- Storage type heaters.
- Instantaneous heaters.
- Semi-instantaneous heaters.
- List five types of hot water heaters using the direct heating method?
- An oil-fired hot water heater.
- An electric water heater.
- The gas-fired (under-fired) water heater.
- An instantaneous, tankless water heater.
- Point of use domestic hot water heater.
- Components of a gas-fired water heater?
- Auto gas control.
- Heat sensor.
- Thermocouple.
- Burner.
- Flue baffles.
- Draft diverter.
- Vent (flue).
- Cold water inlet.
- Dip tube.
- Anti-siphon hole.
- Anode rod.
- Hot water outlet.
- Temperature and pressure relief valve.
- Pipe to floor drain from T&P relief valve.
- Insulation.
- Drain valve.
- Parts of gas-fired instantaneous water heater?
- Gas inlet.
- Gas valve.
- Slow ignition device.
- Thermocouple lead.
- Pilot pipe.
- Pilot.
- Gas cock:
A. Manual gas cock handle.
B. diaphragm.
C. High pressure duct.
D. Pressure duct.
E. bearing plate.
F. Push rod.
G. Gas valve seat.
H. Gas valve spring. - Burner.
- Combustion chamber.
- Heat exchanger.
- Cold water inlet.
- Venturi.
- Transfer coil.
- Hot water outlet.
- What are examples of an indirect heating method?
- A solar domestic hot water supply system.
- A heating coil that conveys hot water or steam from a boiler (or other remote heat source) to a hot water storage tank.
- Parts of a solar domestic hot water supply system?
- Solar collectors.
- Heat exchangers.
- Storage tanks.
- Backup heaters,
- Pumps.
- Controls.
- List three ways heat energy is transmitted to water?
- Conduction.
- Convection.
- Radiation.
- What is conduction?
The heat energy transmitted by solids.
- What is convection?
Process of heat travel with liquids or air. Substance that is heated is lighter and for that reason travel upward starting the gravity circulation.
- What is radiation?
Radiation is a process in which energy is transmitted by heat rays.
- What are two specific classes of installation for almost all water heaters?
Residential and commercial/industrial.
- Why are there differences in the type of construction water heaters?
The design of commercial maybe different to meet special job situations not encountered in residential work. Commercial must meet requirements of American gas association or Underwriters laboratories, National sanitation foundation, ASME.
- List the reasons for the popularity of direct heat water heaters and residential and commercial/industrial applications?
They are adaptable to widely varying job requirements by installing them as a single unit or in multiple units. They are mass-produced, self-contained units that are relatively simple to install, operate and maintain. The heat energy may be provided by gas, electricity, or oil any of which are generally available.
- List five flue designs which provide heat transfer for hot water storage heaters?
- Center flue.
- Multiple flue.
- External channel flue.
- Full floating with external flue.
- Full floating with internal flue(s).
- Source of fuel for gas-fired water heater?
- Natural gas.
- Manufactured gas.
- Propane gas.
- Give a brief description of the function of a gas-fired water heater?
They are particularly susceptible to loss of efficiency and to malfunctions(puffs or explosions) if the source of combustion air is inadequate. Combustion efficiency vary by the types of burner:
- Atmospheric - 75%.
- Forced-draft - 80%.
- Condensing-type - 90-95%.
- How can safety of a gas-fired hot water heater be compromised by?
- The lack of adequate air for combustion.
- An improperly sized or improperly installed gas vent or chimney.
- Incorrectly located operating controls.
- Typical components of energy saver and high recovery gas fired water heaters?
- Tank.
- Insulation.
- Jacket.
- Gas supply.
- Thermostatic controller (rod-and-tube type).
- Sensing element.
- Thermocouple and pilot burner.
- Main gas burner.
- Combustion chamber.
- Crown.
- Flue.
- Flue baffle.
- Draft diverter.
- Cold inlet.
- Dip tube.
- Anti-siphon tube.
- Hot outlet.
- Temperature and pressure relief valve.
- Relief valve discharge.
- Sacrificial anode rod.
- Drain cock.
- In larger commercial installations, the most commonly used gas-fired hot-waters are of the following types?
- Hot-water supply boilers.
- Instantaneous heaters.
- Combined automatic heater and storage tank.
- Circulating hot-water heaters used with a storage tank.
- Types of oil-fired water heaters?
- Generally direct-fired and have forced-draft burners.
- Fully automatic in operation and are provided with a storage tank.
- Larger installations may include hot-water boilers, instantaneous-type heaters, or circulating-type heaters with an associated storage tank.
- What does the fuel oil grade number indicate?
The viscosity of it.
- What fuel oil is used for oil-fired water heaters?
- Number 3 fuel oil or domestic fuel oil is most widely used, except in very large installations.
- Light-grade fuel oils are generally used to minimize repairs and maintenance.
- How does a layer of oil soot reduce the efficiency of the oil-fired heater?
A layer of soot only 1/8” thick may result in a loss of efficiency of about 10%.
- How are electric water heaters made?
Fully automatic and have a storage tank, one or more electric heating elements along with operating and safety controls.
- The use of an electric water heater is advantageous because:
- This type of heater does not require a supply of combustion air.
- It does not require venting to the outside.
- It does not require a chimney.
- It is inherently a clean system, no soot or grime is generated, and it may be installed in areas of a building where a heater fired by a fossil fuel may be impractical.
- It may reduce space requirements for a heater.
- The possibility of fuel leakage is eliminated.
- List some of the tank and tank lining materials used by water heater manufactures to provide maximum tank life?
- Glass (ceramic lining).
- Galvanizing today is changed for cross-linked polyethylene and copper plating .
- Stone lined tank that are coated with a cement-like material.
- Stainless steel, monel, aluminum, or copper-base alloys as tank materials.
- What are magnesium anodes?
Mag rods are form of a stand by protection, used to plate the steel in the event of tank lining damage or failure. A film of magnesium is transferred (by electroplating) from the rod to the inside of the tank wall.
- Whit is a third way that heater manufacturers design long life into their products?
By eliminating or insulating unlike metals within the tank.
- Name a threaded openings welded into the hot water heater tank?
Spuds.
- List spuds of a typical hot water heater by location and purpose?
1. In top of the tank: A. Cold water inlet. B. Hot water outlet. C. Anode rod opening. 2. On the side of the tank: A. Temperature (thermostat) control opening. B. Drain valve opening.
- Use of female threaded openings on the side of the tank of some water heaters?
They can be used to furnish space heating along with domestic water service.
- Why does the cold water inlet at the top of a domestic hot water heater use a dip tube?
Factory installed dip tubes are designed to the correct length. If a dip tube duties orates and breaks off the incoming cold water short cycles and mixes with the outgoing hot water, leaving the customer with little or no hot water.
- What would happen if a dip tube is accidentally installed on the outlet (hot) side?
The effect on the amount of hat water delivered to the customer is dramatic.
- How should the hot water and cold water connections be made?
- Copper to iron pipe adapter must be installed to make the transition.
- Metallic pipe connections within a specified distance above the heater if plastic piping materials are used in piping.
- A shutoff valve be installed close to the cold water inlet.
- What are categories apply to water heating systems?
- Up-fed.
- Down-fed.
- A combination of both.
- A gravity system.
- A forced circulation system.
- No circulation at all.
- What are broad categories apply to water heating systems with regard to temperature?
- One temperature.
2. Multiple temperatures.
- What are one temperature hot water supply systems?
- Instantaneous system for car washing and photo processing with constant demand and no storage.
- Recovery systems with storage.
- A commercial booster heater for the sanitizing rinse in a dishwasher.
- Where are multiple temperature water supply systems that are used to heat water to various temperatures usually found?
Food service water heating systems usually require 140F water for general purposes and 180F water for the dishwasher rinse.
- Types of multiple temperature water supply systems?
- Tank water heater make 180F water. Water mixing valve is set for 140F.
- Large size water heater preheat water to 140F and booster water heater make 180F water.
- Water heater make 180F water and storage tank produce 140F water.
- Steam boiler maintain 180F water from storage tank and water mixing valve make 140F water.
- List four types of piping materials that are available for use in a normal hot water installation?
- Copper.
- Brass.
- Steel.
- Plastic.
- List six types of valves generally used in a hot water distribution system?
- Gate valve.
- Check valve.
- Balancing valve.
- Ball valve.
- Butterfly valve.
- Parts of gate valve:
A. Solid wedge,
B. Split wedge?
- Body.
- A. Solid wedge disc.
B. split wedge disc. - Stem.
- Hand wheel.
- Identification plate.
- Union bonnet.
- Gland.
- Packing.
- Packing nut.
- Parts of swing check valve?
- Body.
- Cap.
- Disc.
- Disc carrier.
- Disc lock-nut.
- Hinge pin.
- Parts of lift check valve?
- Body.
- Cap.
- Disc.
- Parts of balancing valve ?
- Body.
- Core or plug.
- Port (in core or plug).
- Lock nut.
- Parts of globe valve?
- Body.
- Disc.
- Disc lock-nut.
- Stem.
- Hand wheel.
- Identification plate.
- Bonnet.
- Packing.
- Packing nut.
- Parts of ball valves?
- Body.
- 2 seats.
- Ball.
- Retainer.
- Stem.
- Stem packing.
- Gland nut.
- Handle nut.
- Parts of butterfly valve?
- Disc.
- Lower stem.
- Upper stem.
- Stem retainer.
- What are the function of the valves used in a hot water distribution system?
- Ball and gate valves - primarily to isolate the various portions of the system and are sometimes installed as convenience valves for maintainable purposes.
- Globe valves - used when a throttling operation is desired and for shutoff purposes.
- Check valves - prevent reverse flow in hot water supply system.
- Balancing valves - equalize circulation throughout a hot water supply system.
- Butterfly valves - as balancing valves and are sometimes used to isolate sections of a piping system.
- List the names of the major parts of a domestic hot water supply system?
- Mains.
- Risers.
- Major branches.
- Minor branches.
- Terminal points.
- Circulating lines.
- Describe the route the hot water takes to reach the terminal points?
The heated water passes from the heater into water mains which are generally the largest diameter puppies in the system. The mains distribute the water primarily to risers and major branches. Risers and major branches connect to minor branches which reach the terminal points in the system.
- How does the heated water deliver to the terminal points at the desired temperature?
By means of circulating lines.
- What is the difference between the operation of a gravity circulating system and a forced circulating system?
Gravity circulation can be obtained when the water heating equipment is located below the level of hot water use. Return lines are provided to permit circulation of the water. When it will cool it will travel by gravity through the return lines back to heat source.
Forced circulation requires the use of a circulating pump. The pump is operated by an automatic temperature control or heat sensing device such as an aqua stat, located at the end of the circulation loop. The control is set to start the pump whenever the water temperature cools to a pre-determined minimum and shutoff it when the water at the end of loop is up to max temperature.
- How do the circulating lines relate to the rest of the system?
The circulating lines leave the ends of the risers and the branches and tie back into a main circulating line (HWR). It is almost the same as the hot water distribution system in that each system has a main, risers and branches.
- Types of domestic hot water circulation systems which operate by gravity?
- Conventional up feed system.
- Conventional down feed system.
- Conventional combination up feed and down feed system.
- What causes the gravity (natural) circulation in gravity domestic hot water circulation systems?
Circulation by gravity occurs in the se systems because the density (weight) of water, decreases with an increase an increase in temperature, and because arrangement are made in the piping system for the hottest water to rise and the coldest water to settle, thus causing circulation within the system.
- Types of invert domestic hot water circulation system?
- Inverted up feed system.
- Inverted down feed system.
- Inverted combination down feed and up feed system.
- Why are the circulating pumps required on the inverted domestic hot water supply system?
Systems have their heat source at the top of, or above the distribution system. Since gravity circulation works by cooler water flow downward to a heat source, a circulation pump must be used to revers the flow.
- Would there be any variation in pressure at the base of hot water and its return risers?
Theoretically, a difference of about 1/2 psig would occur for 100’ tall risers, because return is cooler (100F) than supply (140F) and for that reason heavier (61.998 lb per cu. foot) than supply (61.386 lb per cu. foot).
- Under normal conditions, when would a circulating pump be needed in a hot water system designed with the heat source below the piping?
The system is located in a one or two-story buildings, the height of the hot water risers might must not be sufficient to produce gravity circulation.
Generally speaking, if a point of use is located at a distance of 100’ or more away from the heat source, a circulation system with a circulating pump should be installed.
- What causes air pockets to develop in closed pressurized piping such as a hot water supply system?
When a system is filled with water bubbles of air are trapped against the side and top walls of piping. Dissolved air in water is often liberated when the water is heated and this air also accumulates at the high points in the system.
- Why do air pockets slow down or stop sirculation?
A closed piping system under pressure produces equal static pressure in all portions of the system. Pressure equalize in the system and compress the air slightly. The air will always remain at the highest point in the system to block circulation because the air will compress rather than move.
- Types of pump for a circulating hot water system?
Low-head pumps (pumps that produce only low pressures).
- How can accumulation of the air be eliminated from a domestic hot water supply system?
- By placing automatic air vents at high points in the system.
- By placing a fixture outlet at the high points in a system.
- How does a popular type of air vent operate?
A hollow ball that floats against a seat in the vent outlet to stop the passage of water. If air is present ball doesn’t float, and thus the air escapes through the vent outlet.
- Explain how can domestic water be heated by an indirect-fired hot water heater installed in the same boiler that heats a building?
High-efficiency combination boilers and indirect-fired water heaters are used. The hot water storage tank-within-a-tank design features a corrugated stainless steel inner tank; steel outer tank.
- Parts of indirect-fired hot water storage tank?
- Enameled steel jacked.
- Rigid polyurethane insulation.
- Steel outer tank.
- Circulating boiler water.
- Boiled supply water inlet.
- Boiled return water outlet.
- Corrugated stainless steel inner tank.
- Domestic could water inlet.
- Domestic hot water outlet.
- CPVC dip tube.
- Thermostat remote sensing bulb.
- Adjustable thermostat.
- Electrical connection.
- Built-in manual air vent.
- How do you size combination boiler and indirect-fired domestic hot water storage tank?
The most common rating is the maximum number of gallons of hot water available in one hour: 115F domestic water supply, 50F inlet water and 200*F boiler water supply to the water heater.
- Priority of heating cycle of combination boiler and indirect fired domestic water heater?
- Domestic: when the storage tank calls for heat, boiler water is switched from the heating system to the tank.
- Non-domestic: the heating system and the storage tank share the energy available from the boiler and the storage tank operates as a separate zone.
- What absorb expansion in hot water supply system?
- Expansion loops.
- Swing joints.
- Mechanical expansion joints.
- Give several examples of the piping arrangement for various types of indirect heat domestic hot water supply systems?
- High efficiency boiler, priority valve, DWC heat exchanger, DWC circulator/adapter, water heater storage tank,
- High efficiency boiler, DWC circulator/adapter, tankless heater.
- Boiler, water heater with circulator, priority valve, 1st radiation load with circulator, .2nd load with circulator.
- Boiler, circulator, water heater with zone valve, priority valve, 1st radiation load with zone valve, 2nd radiation load with zone valve.
- Parts for combination hot water heating and domestic hot water installation?
- Cold water supply.
- Shutoff valve for water heater.
- Pre charged expansion tank.
- Water heater.
- Thermostat control.
- Combination temperature and pressure relief valve.
- Domestic hot water supply.
- Shutoff valve for boiler.
- Double check valve with atmospheric vent with drain and air gap.
- Pressure reducing valve.
- Hot water heating boiler.
- Pressure relief valve.
- Domestic hot water circulator.
- Check valve on the line to water heater.
- Pre charged expansion tank on hot water heating system.
- Check valve on heating system.
- Hot water heating circulator.
14 domestic hot eaterci
- Construction of a double check valve with an intermediate atmospheric vent?
- Union inlet connection.
- Stainless steel strainer screen.
- Primary check valve.
- Vent and drain connection.
- Secondary check valve.
- Union outlet connection.
Brass body, stainless steel working parts.
- Equipment required for a hydronic heating system?
- Shutoff valve.
- Double check valve with atmospheric vent and drain with air gap.
- Pressure refusing valve.
- Tee on the cold water fill line to compression tank.
- Tank fitting.
- Compression tank.
- Boiler fitting.
- Flow control valve.
- Balances on return lines .
- Booster pump.
- ASME relief valve.
- Pressure setting an ASME pressure relief valve of a hydronic heating system?
To relieve water or steam if the pressure exceeds 30 psig.
- Why is more critical demand placed on a safety relief valve in hydronic heating system?
- Pound of water converted to the steam increases in volume 1,700 times.
- The emergency stage is coursed by an over-firing of the burner. The heating system can not dissipate the heat energy as fast as it is developed in the boiler, and temperatures and pressures continue to rise.
- Give a brief description of the function of flow-control valve?
Stop over heating from gravity circulation in hot water heating systems usually by means of a positive-closing, precision-machined, brass-to-brass seat and disc.
- How shall you choice pressure relief valve?
Pipe size, relief pressure (operating), and Btuh rating are the same on the valve nameplate and boiler one.
- Why are pre charged expansion tanks installed in a forced hot water heating system?
In lieu of a compression tank.
- What does a pre charged expansion tank combination packages includ?
- Tank.
- An air scoop.
- A float type. air vent.
- What is an air scoop?
In-line air separator.
- Explain how does the pressure reducing (boiler fill) valve, automatically feeds cold water into a heating system whenever the system pressure falls below some predetermined level?
Factory set to open when the system pressure declines to less than 12 psig. They should be adjusted when necessary to provide a maximum of 4 psig at the highest point of the system. It does not protect the boiler from a lower water condition if the system pressure is above 12 psig.
- Types of pressure reducing valves boiler fill) valves?
- It’s not equipped with a fast fill features.
- Equipped with a fast fill feature.
- As a combination backflow preventer and boiler fill valve.
- Dual unit - combination relief and pressure reducing valves without fast fill feature.
- Dual unit with fast fill feature.
- Typical installation of pressure reducing valve serving a hot water heating system?
Cold water supply: 1. Shutoff valve. 2. Strainer. 3. Backflow preventer with air gap and drain. 4. Pressure reducing valve. Boiler: 1. Hot water supply line with cold water supply connection tee. 2. Return line with shutoff valve. 3. Relief valve. Hot water supply line: 1. Combination package of a pre charged expansion tank. 2. Shutoff valve. 3. Circulating (booster) pump 4. Triple duty valve.
- Give a brief description of the air control system consist of an air-tight compression tank, a boiler fitting and a tank fitting?
The combined function of the two fittings is to separate free air (as it is released at the point of highest temperature and lowest velocity in the boiler) and put that air in the compression tank , where it can effectively act as a cushion against changing system pressures.
- What can the boiler fitting consist?
A tube inserted in a T-shaped fitting. The tube extends from the supply main down into the boiler water and prevents air which accumulates at the top of the boiler from rising into the supply piping and heating units.
- Types of air control boiler fittings?
- Top outlet air control boiler fittings:
A. Supply main size 1”-4”.
B. supply main size 6”8”. - Side outlet air troll boiler fittings.
- How are top outlet air troll boiler fittings installed?
- Size 1”-4” with a short nipple .
- Size 6”-8” require a separate top opening in the boiler for connecting the line to the compression tank and the flanges (welding or screwed type) for adjustable dip tube.
- How are air control tank fittings are sized?
As required by the diameter of the compression tank.
- Types of airtrol fittings?
- ATF.
- ATFL with vent tube cut 2/3 the diameter of tank installed in separate manual air vent.
- Valve types compression tank fittings.
- Size and pitch the horizontal pipe between the ATFL fitting and the boiler?
Pich-up to tank at least 1” in 5’ and min 1” diameter or 1 1/4” for more than 7’ long up to 20’ and 1 1/2” for longer pipe.
- Describe the operation of the valve type compression tank fittings?
All free and entrained air collected by an air separator, or other air collection device, is routed through the tank fitting , and it allows air to pass freely into the compression tank. When the 1/8” plug is removed additional air is admitted into the tank when valve is open and drain water from tank.
- Types of inline air separators?
- Large size centrifugal type air separator.
2. Air separator with built-in dip tube.
- Explain how are in-line air separator used as a low velocity area when a boiler is not available or usable as the point of air separation?
Water and entrained air enter the air separator where the velocity is reduced because of the large volume of the separator. Air separates out as velocity is refused rising to the top of the separator. The air now enter the pipe., leading to the compression tank.
- Where can in-line air separator fitting be installed?
- On the top outlet boiler instead airtrol boiler fitting.
- On the side outlet boiler instead side outlet boiler fitting.
- On hot water steam converter supply line.
- Parts of hot water steam converter?
- Steam in line.
- Heat exchanger.
- Condensate out line.
- Cold water supply line to air separator:
A. Shutoff valve.
B. pressure reducing valve with double check valve (atmospheric vent).
C. Tee to air separator and compression tank through tank fitting. - Supply line from air separator with pressure relief valve.
- Return line to heat exchanger.
- Expansion tank with accessories?
- ASME expansion tank.
- Tank fitting.
- Tank drain.
- Sight glass tappings.
- Parts of in-line air separator with booster pump installed in system supply?
- Boiler with pressure relief valve.
- Air separator with a booster pump on supply line.
- Cold water supply line with compression tank line.
- Compression tank with tank fitting .
- Pressure reduction valve, double check valve with atmospheric vent, shutoff valve.
- Return line to the boiler with drain valve.
- Describe the application of several types of circulating pumps which can be used to circulate water in a hot water heating or in a domestic hot water supply system?
- Provide zone control in a multiple zone hydronic heating system.
- Used to circulate boiler water through a heat exchanger to provide domestic hot water.
- A single booster pump in hydronic heating system using zone control valves.
- It will operate equally in the return piping as well if installed in the supply piping of the hydronic heating system.
- Types of circulating pumps in a domestic hot water supply system or in a hot water heating?
- The in-line circulating pump.
- End-suction close-coupled pump.
- Ends unction base mounted with flexible coupling.
- How are in-line centrifugal pumps sized?
According to rated capacities of delivery in gallons per minute(gpm) and head pressure in feet of water.
- What is a residential type zone control valve?
It is usually an electrically operated valve that will open fully on a call for heat from a thermostat located in an area or zone supplied by this valve. When the zone is satisfied, the thermostat will de-energize the valve, causing it to close.
- Difference between residential and commercial type zone control valve?
Commercial are designed to function in a similar manner either by electric or pneumatic operation.
- Types of zone control valves?
- Two wire motor operated type.
2. Four wire motorized type.
- How should the zone control valve be used?
- With a 24 volt two wire thermostat with a 0.6 ampere heat anticipatory.
- A maximum of three zone control valves can be installed using 115/24 volt transformer rated at 40 VA (volt amps). It must be dedicated to the zone control valves and must not be used to power any other device.
- How shall you join two s circuit in a single zone ?
- Supply Tee.
- Tee to 1st and 2nd circuit.
- Tee from circuits to return line.
- Tee on return line.
- Explain how the air trapped in the tank and, acting as a cushion or compressed spring , supplies pressure to all parts of the system?
Every times the burner goes on and the water expands, the relief valve will discharge. Every time the burner goes off and the pressure in the system reduces, fresh water will be fed into the system. All of this can be avoided by correctly installing proper types of air-control equipment.
- How must all piping be pitched in hydronic heating system?
So that air in the system can be vented either into the expansion tank or from automatic or manual air vents.
- What should be done when piping must be run around an obstacle?
It is advisable to drop the piping below the beam and install drain valve at lower point. If it is looped over the beam, it will be necessary to provide for venting of air from the high point of the pipe.
On series loop systems, it is possible to eliminate all manual air vents in the system and use a single purge valve at the return to the boiler.
579.. How are high points in heating system piping vented?
Air vent fittings and accessories available for the elimination of trapped air in hydronic heating and cooling systems. In large systems, vent tubing from the system high points can be assembled in a manifold at some convenient point in a mechanical room or other location.
- Types of vent fittings?
- Manually operated air vents.
- Float type air vent.
- Air purger with float vent.
- Why should eccentric fitting be used when changing the size of horizontal runs of pie?
To keep the tops of the pipes in line to permit free passage of air along the inside of the pipe.
- How are piping circuits laid out and installed in the case of divided circuiits?
- The return ends of the supply mains can be dropped directly into a pump header connected tithe boiler.
- Do not use bull head connections on the return piping of divided circuits to the boiler.
- Square head cocks, combination balancing and purging valves or circuit setters should be used to regulate the flow of water in several circuits of return piping to a boiler.
- Where are low head pumps usually installed?
On either the supply or return piping, usually at a location in close proximity of the boiler. Return piping is the most common location.
Installation section of straight pipe five times the diameter of the suction pipe size between the suction side of the pump and first elbow.
Install a square head , or combination purge and balance valve, and a check valve in the discharge pipe close to the pump. The check valve should be between the square head valve and the pump discharge nozzle.
Do not try to hold the pump up by putting a support under the motor, misalignment will occur.
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- What must be done after the installation of the a pump is completed?
The pump and motor must be lubricated immediately.
- How are low head (circulating) pumps generally considered?
As pumps having 1/2 hp motors or less and operating below 12’ of pressure head . A low head pump is less than the static height (operating pressure) of the system.
- How can low head pumps be installed?
Circulating (booster and in-line centrifugal) pumps can be installed to pump either up or down or to the left or right. This can be accomplished by separating the bearing assembly from the pump body and rotating the body until the arrow points in direction of water flow.
- What is a heat exchanger?
A heat exchanger is a pressure vessel designed for operation at certain specific limits of pressure and temperature.
- What are the most frequent cause of nonperformance of heat exchanger?
Improper venting and fouling. Be sure that both sides of the exchanger are clean, carefully vented and full of fluid.
- Typical installation of steam heat exchanger when used with storage tank?
- Cold water line with shutoff valve and pressure relief valve to the farther bottom corner of hot water storage tank.
- Worm water line to the heat exchanger with all bronze circulating (booster) pump controlled by tank temperature control.
- Steam in line with steam control valve controlled by devise on heat exchanger outlet.
- Condensate line to steam trap from exchanger.
- Air vent or vacuum breaker on heat exchanger.
- Top hot water line to hot water storage tank.
- Domestic hot water line from the top of storage tank.
- Typical installation of heat exchanger when used as an instantaneous heater?
- Line from boiler to heat exchanger with flow-control valve.
- From heat exchanger to boiler with circulating (booster) pump.
- Cold water line to heat exchanger with shutoff valve and pressure relief valve.
- Domestic hot water line to tempering valve with circulating pump control.
- What type of heat exchanger is available for installation in hot water heating boilers?
- For domestic and commercial service hot water.
- For industrial process water.
- For pool heating.
- For hot water radiation heating.
- For snow melting.
- For hot water space heating.
- For hot water radiant heating.
- Recommended piping for heat exchanger in hot water heating boilers in apartment house?
- Space heating:
A. Hot water supply to heating system with shutoff valves.
B. return water from heating system with circulator and shutoff valve.
C. Boiler expansion tank with a shutoff valve. - Tankless indirect heating coil for domestic hot water:
A. Cold water supply through shutoff valve and check valve to a) recirculation line, b) tempering valve.
B. Recirculating line with shutoff valve, strainer and circulator pump to the cold water Tee, drain valve, coil relief valve to the boiler.
C. Tempered water to fixtures with thermometer and shutoff valve. - Indirect heating coil for swimming pool heating:
A. Heated water to pool line with Tee to by-pass valve.
B. return water from pool filter to by-pass Tee with temperature control and pool temperature control valve to boiler.
- Recommended piping for heat exchanger in hot water heating boilers in motel - hotel?
- Space heating line:
A. Hot water supply line to heating system with shutoff valve.
B. return water from heating system with shot off valve to boiler.
C. Boiler RV.
D. Expansion tank. - Indirect heating coil for domestic hot water storage tank application:
A. Hot water line to storage tank with coil relief valve, expansion tank, shutoff valve.
B. circulation line from storage tank to boiler coil with circulator, shutoff valve and drain valve.
C. Storage tank with relief valve.
D. Hot water line to tempering valve with shutoff valve.
E. tempered water line from tempering valve with thermometer and shutoff valve.
F. Recirculation tempered water line to storage tank with check valve, shutoff valve and circulator to cold water supply Tee, and after to storage tank with shutoff valve.
G. Cold water supply lines to a) tempering valve with check valve and shutoff valve, b) recirculation tempered water line with shutoff valve and check valve.
- Recommended piping for heat exchanger in hot water heating boilers in restaurant?
- Steam line for steam tables:
A. Supply line with shutoff valve.
B. condensate return with shutoff valve.
C. RV. - Indirect heating coil for domestic hot water storage tank application:
A. Hot water supply to storage tank with expansion tank and RV, shutoff valve.
B. circulation line with circulator, shutoff valve and drain valve.
C. Storage tank with relief valve.
D. Hot water line to tempering valve with shutoff valve from storage tank.
E. tempering water line from tempering valve with thermometer and shutoff valve.
F. Tempered recirculation line to storage tank with check valve, shutoff valve, circulator, cold water supply Tee shutoff valve.
G. Cold water supply lines to a) tempering valves with check valve and shutoff valve, b) recirculation line with shutoff valve and check valve. - Indirect heating coil for snow melting:
A. Hot water supply with expansion tank that has shutoff valve and anti-freeze fill with shutoff valve, RV, shutoff valve.
B. return water line with cold water supply Tee, circulator,!shutoff valve, drain valve.
C. Cold water supply to return water Tee with check valve, shutoff valve, pressure reducing valve.
- Recommended piping for heat exchanger in hot water heating boiler in factory?
- Steam line for process or space heating:
A. Steam supply line with shutoff line.
B. condensate return line with shutoff valve.
C. Boiler relief valve. - Tankless indirect heating coil for domestic hot water:
A. Hot water line to tempering valve with shutoff valve .
B. Tempered water to fixtures from tempering valve with thermometer and shutoff valve.
C. Recirculation line to cold water supply Tee with shutoff valve, check valve and circulator.
D. Cold water supply line to tempering valve Tee with shutoff valve and check valve. After that Tee to circulation line Tee and to heating coil through check valve, drain valve, coil relief valve. - Indirect heating coil for hot water space heating:
A. Hot water supply to heating system with boiler expansion tank, thermometer, shutoff valve.
B. return water from heating system with cold water supply Tee, circulator, shutoff valve, drain valve.
C. Cold water supply to return water from heating system Tee with check valve, shutoff valve, pressure reducing valve.
- Recommended piping for heat exchanger in hot water heating boilers in Multi-purpose system?
- Space heating line:
A. Hot water line to space heating from Tee connecting two boilers. From boiler hot water outlet to that Tee through shutoff valve.
B. return from space heating to boiler manifold Tee and to separate boilers through insulating valve.
C. Expansion tank, pressure gage, pop safety from boiler.
D. Cold water supply with pressure reducing valve and check valve to boiler. - Hot service water:
A. From heat exchanger to tempering valve with shutoff valve.
B. from tempering valve to hot service water manifold with thermometer and insulation valve.
C. Cold water service to circulation return Tee with shutoff valve and check valve.
D. Circulation return to cold water service Tee with circulator pump that keep continuous operation.
E. line from Tee cold water service and circulation return to heat exchanger manifold.
F. From heat exchanger manifold Tee to Tee serving separate boilers and from that Tee to tempering valve through shutoff valve and other branch to heat exchanger through insulation valve, drain valve , pressure relief valve.
- Recommended piping for heat exchanger in hot water heating boilers with vertical type storage tank?
- Water heater connections.
A. Water heater fill/make-up line with boiler fill valve and shutoff valve.
B. boiler drain valve.
C. Expansion tank with insulation valve and expansion tank drain.
D. Boiler relief valve.
E. supply space heating connection.
F. Return space heating connection. - Heat exchanger lines:
A. To storage tank with exchanger relief valve and tank insulation valve.
B. circulation line with tank drain valve, tank insulation valve, steamer, exchanger circulator, tank temperature control, exchanger drain valve. - Storage tank lines:
A. Cold water supply with check valve, insulation valve and diffuser pipe.
B. hot temperature system circulation return line with circulator, check valve and insulation valve.
C. High temperature water to fixtures at tank temperature control setting with insulation valve to tempering valve tee.
D. Combination temperature and pressure gauge.
E. tank temperature control.
F. Tank limit control.
G. Tank relief valve. - Tempering valve lines:
A. High temperature water line with insulation valve.
B. cold water supply line with check valve, insulation valve, 27” riser pipe to Holby valve Tee.
C. Low temperature system circulation return to Tee with circulation pump, check valve, insulation valve.
D. Line from Holby valve to circulator and cold water Tee with union.
E. Low temperature line at tempering valve setting with insulation valve and thermometer.
- Translate name “ruchnyj nasos kolonka”?
A piston type lift pipe commonly known as a pitcher pump.
- Describe the operation of a piston type lift pump?
When handle pressed down piston going up and atmospheric pressure in water well open bottom check valve to let water in. When handle lifted up piston going down closing bottom check valve and pushing water up through upper check valve.
- What is a reciprocating pump?
It can be described as pumps that have a backward and forward or an upward and downward motion.
- Types of reciprocating pumps?
- Pitcher pump.
- Air compressors.
- Boiler feed pump.
- Deep well piston pumps (for water or oil).
- Hydraulic power pumps.
- Vacuum pumps.
- Diaphragm type ditch pumps.
- Hydrostatic test pumps.
- What is double acting pump?
The valves and piping are arranged to allow a positive discharge on the return stroke as well as the primary stroke.
- What are the differences between a piston pump and a plunger pump?
The piston is shorter than the stroke and seal is on the piston. The plunger is longer than stroke and the seal is on the cylinder.
- What is diaphragm pump?
It employs a substance such as rubber or neoprene in place of piston or plunger to remove water from trenches, flooded foundations, drains and other places where there is a high proportion of mud, silt or sand to water.
- Parts of diaphragm type pump?
- Suction accumulator.
- Suction.
- Suction Check valve.
- Diaphragm pot.
- Diaphragm.
- Plunger spring.
- Eccentric.
- Gear box.
- Oil cup.
- ! Discharge check valve.
- Discharge.
- What type of positive displacement pump discharges fluids in a smooth flow?
The rotary gear pump.
- Common use of rotary gear pumps?
- Pump fuel oil in oil burners.
- Pumping of the high pressure hydraulic fluid which provides the power to operate hydraulic pistons on backhoes, loaders and other hydraulic equipment.
- For pumping viscous fluids.
- What type of pumps are often used in refrigeration systems?
The lobe and slinging vane type rotary pumps.
- What is another classification group from positive displacement pump?
Non-positive displacement pumps. This would include centrifugal pumps, propeller pumps, and special pumps such as jet pumps and hydraulic rams, etc.
- What are the characteristics of a centrifugal pump which make it so popular for use in piping systems?
They generally cost less and perform economically and reliably throughout various pressures and flow rates. They can produce up to several thousand feet of head, they can handle liquids up to 1000*F, and they can pump abrasives and solids.
They have few moving parts and if properly installed and serviced, will last a long time with little maintenance, can be easily modified. They can tolerate considerable corrosion and erosion before their performance is substantially affected.
- How does oxygen cause corrosion?
Air dissolved in water consist of about 30% oxygen. It degrades metals through an electro-chemical process of internal oxidation.
- Four examples of closed systems using centrifugal (circulating) pumps are?
- Hydronic hot water heating.
- Chilled water.
- Domestic hot water.
- Condenser water.
- What is centrifugal force?
The force generated by rotation which acts directly outward from the center of rotation.
- What is the major difference in the design volute centrifugal pump and diffusion or turbine pump?
The rotating impeller is surrounded within the casing by stationary guide vanes. The diffusion vanes provide gradually expanding passages in which the direction of flow is sharply changed.
- Use of diffusion or turbine pumps?
They are applied to high pressure and, at times, in combination with high temperatures. Turbine pumps having top centerline discharge are self-venting and have the ability to handle vapors without vapor lock. This characteristic allows handling of boiling liquids and liquefied gasses at suction heads slightly over the vapor pressure.