Plumbing Flashcards
Potable water is
a. water people can safely drink.
b. well water.
c. water suitable for cooking and washing but not drinking.
d. water with an e-coli reading of more than 25.
a. Potable water is water that is safe to drink.
Which of the following statements is true about water flow and pressure in regard to pipes in residential plumbing systems?
a. The pressure is highest when there is no water flowing.
b. The pressure is highest at the outlet point of the pipe.
c. As more pressure is applied to a given pipe length with an open faucet at the end, the flow rate will remain the same.
d. The flow rate in a pipe is greater close to the source than at the outlet.
a. The pressure is highest when there is no water flowing.
Pressure loss due to friction
a. is zero when there is no water flowing.
b. cannot exceed 20 psi.
c. is independent of pipe length.
d. is independent of pipe wall smoothness.
a. There is no pressure loss due to friction when there is no water flowing.
How much water flows through a 3/4-inch-diameterpipe relative to a 1/2-inch-diameter pipe with the same pressure-loss?
a. 150 percent
b. 200 percent
c. 250 percent
d. 270 percent
d. Roughly 270 percent more water will flow through a 3/4-inch-diameter pipe than a 1/2-inch-diameter pipe.
Excess water pressure may lead to
a. excess water velocity.
b. excess friction loss.
c. longer operating periods for clothes washers.
d. splashing and excessive siphoning as toilets are flushed.
a. Excess water pressure may lead to excess water velocity.
If you wanted to fill a bucket, which of the following fixtures with faucets fully opened would fill it the most quickly? (Assume that pipe length, size, and pressure are equal for all of these.)
a. Bathroom basin
b. Kitchen sink
c. Outdoor hose bib
d. Bathtub fill spout
d. The quickest way to fill a bucket is with the bathtub fill spout.
Causes of poor pressure and flow in a house include all of the following EXCEPT
a. undersized piping.
b. rusted piping
c. a gate-valve-type main valve.
d. leaks.
c. A gate valve does not cause poor pressure and/or flow.
Which of the following 1/2-inch-diameter pipes would have the lowest pressure and flow characteristics?
a. A 50-foot pipe with the outlet at the same elevation as the Source
b. A 50-foot pipe with the outlet 20 feet above the source
c. A 100-foot pipe with the outlet IO feet above the source
d. A l00-foot pipe with the outlet 20 feet above the source
d. The lowest pressure and flow characteristics would belong to the 100-foot pipe with the outlet 20 feet above the source.
Which of the following has no effect on water pressure and flow?
a. How smooth the pipe is
b. What the static pressure is
c. How fast the valve closes
d. How high it is being pushed uphill
c. Flow fast the valve closes has no effect on water pressure and flow.
Bored wells are typically
a. deeper than 200 feet.
b. deeper than 400 feet.
c. shallower than 100 feet.
d. 12 inches in dian1eter.
c. Bored wells are shallower than 100 feet.
A submersible pump in a 200-foot-deep drilled well is under 70 feet of water. The top of the well is 15 feet below the basement of the house. How much static head is present?
a. 70 feet
b. 130feet
c. 200 feet
d. 215 feet
a. The static head for a submersible pump 70 feet under water is 70 feet.
If you see three pipes at a jet pump in the basement, it means that
a. the pump is feeding two separate pressure tanks.
b. the well must be deeper than 50 feet.
c. the suction line has been replaced because of obstruction.
d. the venturi is in the well, lake, or river.
d. If you see three pipes at a jet pump in the house, this means that the venturi is in the well, lake, river, or whatever the source may be.
Which of the following is NOT a cause for an inoperative pump?
a. The motor is burned out.
b. The discharge line is split.
c. The control switch for the pump is not working.
d. There is no electricity at the pump.
b. A split discharge line is not a cause for an inoperative pump.
The purpose of the pressure tank is to
a. increase the pressure in the system.
b. prevent the pump from short cycling.
c. decrease the flow rate through the pump.
d. prevent over-pressurizing the supply piping system.
b. The pressure tank helps to prevent the pump from short cycling.
What would the difference be in static pressure readings on a vertical pipe at zero elevation and at a 20-foot elevation?
a. 4.5 psi
b. 9 psi
c. 17 psi
d. 20 psi
b. A 20-foot elevation difference would cause a pressure differential of roughly 9 psi.
What kind of a flow rate from a well is usually considered acceptable?
a. 2 gpm
b. 3 gpm
c. 5 gpm
d. 10 gpm
b. A 3 gpm flow rate is usually considered acceptable from a private well.
Which of the following is the most serious problem with a well supplying water to a house?
a. Less than optimum water quantity
b. A piston-type pump on a well
c. Contaminated well water
d. A well that is too close to the property line
c. Contaminated well water is the most serious problem you can have because it is a life safety issue. Running out of water is an inconvenience but is not life threatening.
Drilled wells
a. are up to 100 feet deep.
b. are often four inches in diameter.
c. need no well casing.
d. cannot have submersible pumps.
b. Drilled wells are typically four to six inches in diameter.
Common well problems include all of the following EXCEPT
a. poor surface grading.
b. missing casing.
c. recovery rate of 10-15 gpm.
d. not enough water.
c. A recovery rate of 10 gpm to 15 gpm is not a problem.
Which of the following pumps definitely does NOT need priming?
a. Jet pump
b. Submersible pump
c. Deep well pump
d. Shallow well pump
b. Submersible pumps do not need priming because they are always surrounded by water.
Typical pump problems include all of the following EXCEPT
a. inoperativeness.
b. excess noise or vibration.
c. excess pressure.
d. running continuously.
c. Excess pressure is not a pump problem.
Common problems with shutoff valves in the house include all of the following EXCEPT
a. missing valves.
b. leaking valves.
c. damaged handles.
d. location in a basement.
d. Shut off valves are frequently located in basements. This is not a problem.
What is galvanic action?
a. Corrosion that occurs when two dissimilar metals touch
b. Connecting ABS and PVC piping together in a plumbing system
c. Gurgling noise in the drain system
d. Failure mode peculiar to brass piping
a. Galvanic action is corrosion that occurs when dissimilar metals contact each other, in a plumbing system, for example.
The water service line diameter from the street to new houses should be at least
a. 1/4-inch.
b. 1/2-inch.
c. 3/4-inch.
d. 1-inch.
c. The water service line diameter from the street to the house in a new construction should be a least 3/4-inch.
The supply water piping diameter inside houses should be at least
a. 1/4-inch.
b. 1/2-inch.
c. 3/4-inch.
d. 1-inch.
b. The supply water piping diameter inside houses should be at least 1/2 inch.
Supply water pressure inside the house should NOT exceed
a. 40 psi.
b. 50 psi.
c. 80 psi.
d. 150 psi.
c. Supply water pressure inside the house should not be more than 80 psi.
Horizontal plastic water pipe should be supported every
a. 4 feet.
b. 12 feet.
c. 20 feet.
d. 1 foot.
a. Horizontal plastic water pipes should be supported at least every four feet. Some areas call for supports even closer together.
A water service line with a pressure of 110 psi will require a
a. reduced-pressure backflow device.
b. expansion tank.
c. Extra-heavy pipe and fittings.
d. pressure regulator.
d. If the water surface line pressure is 110 psi, a pressure regulator would typically be required.
A 40-50-year-old, galvanized-steel water supply system
a. is the best system available.
b. should have the water tested for lead.
c. will probably show reduced water volume and pressure.
d. is not compatible with PVC drain lines.
c. A 40-50-year-old galvanized-steel water supply system will probably show reduced water volume and pressure.
Galvanized-steel pipe typically fails first at
a. threaded connections.
b. elbows.
c. the top sides of long horizontal runs.
d. bends in the pipe.
a. Galvanized-steel pipe typically fails first at the threaded connections, which are thinner.
Which of the following is NOT a backflow prevention device?
a. Vacuum breaker
b. Backflow preventer
c. Isolating valve
d. Backwater valve
c. An isolating valve is not a backflow prevention device.
Which type of plastic piping is typically cream-colored and suitable for use on both the hot and cold water system?
a. PVC
b. CPVC
c. Polybutylene
d. ABS
b. CPVC is typically cream colored and suitable for use on both the hot and cold water system.
Which of the following suggests failing galvanized-steel supply piping?
a. Weaker pressure on the hot side than the cold
b. Weaker pressure on the cold side than the hot
c. Vertical risers replaced with copper
d. Green stains on the insides of plumbing fixtures
a. Weaker pressure on the hot side than the cold side suggest failing galvanized-steel supply piping.
Any brass supply piping you come across will be
a. 3/4 inch diameter.
b. yellow brass, with many years of service left.
c. prone to failure at the horizontal soldered connections.
d. near the end of its life.
d. Any brass piping that you find on the supply system will probably be near the end of its life.
How can you tell the difference between brass piping and galvanized-steel piping?
a. Galvanized steel has threaded connections and brass piping is soldered.
b. Galvanized steel has soldered connections and brass piping is threaded.
c. Brass piping will always be smaller diameter than galvanized steel.
d. Galvanized steel will attract a magnet and brass will not.
d. Galvanized-steel piping will attract a magnet; brass piping will not.
Joining copper and galvanized-steel piping together will produce corrosion unless a(n)
a. isolation hanger is used.
b. dielectric connector is used
.c. tempering valve is used.
d. brass coupler is used.
b. Copper and galvanized-steel piping will corrode each other; unless dielectric connector is used.
Which of the following devices protects against backflow?
a. Double-check valve assembly
b. Atmospheric vacuum breaker
c. Pressure-type vacuum breaker
d. Pressure regulator
a. Double-check valve assembly
Gas-fired water heaters and boilers for space heating both have all of the following components EXCEPT
a. gas piping and a gas burner.
b. a cold water inlet pipe.
c. a temperature/pressure-relief valve set at 210°F and 150 psi.
d. a venting system.
c. Boilers and water heaters that are gas-fired typically have all of these components except a temperature/pressure-relief valve set as 210°F and 150 psi. Boilers typically use a pressure-relief valve set at 30 psi.
Gas fired water heaters have
a. an expansion tank.
b. potable water.
c. an operating pressure of 12-15 psi.
d. operating temperatures of 180°F, typically.
b. Gas-fired water heaters see potable water.
Gas-fired and oil-fired water heaters have all of the following EXCEPT
a. dip tubes.
b. insulated tanks
.c. sacrificial anodes.
d. lower recovery rates than electric water heaters.
d. Gas-fired and oil-fired water heaters have faster recovery rates than electric water heaters.
Which water heater has the fastest recovery rate?
a. Single-element electric heater
b. Double-element electric heater
c. Oil-fired water heater
d. Direct-vent, gas-fired water heater
c. An oil-fired water heater has the fastest recovery rate.
Which of the following is NOT a common problem with gas piping?
a. Threaded connections
b. Leaks
c. Rusting
d. No drip leg
a. Threaded connections are not a problem with gas piping, which is usually steel.
Gas meters
a. must be located outside.
b. are never undersized.
c. never leak.
d. may ice up.
d. Gas meters may ice up.
Which of the following natural gas piping arrangements is NOT permitted in any jurisdiction?
a. Plastic pipe used underground outdoors
b. Plastic pipe used indoors
c. Coated steel piping used outdoors underground
d. Black steel piping used indoors
b. Plastic pipe cannot be used indoors.
All of the following are common problems found on gas piping EXCEPT
a. leaks.
b. excess pressure.
c. rusting.
d. improper connections.
b. Excess pressure is not a common problem on gas piping.
Which of the following is NOT TRUE about indoor oil tanks?
a. The tank should be 10 feet away from any burner.
b. Tanks may rust over time.
c. Rusting of tanks is common at the bottom weld if there is water in the tank.
d. Outside tanks were never buried.
d. Oil tanks outside were often buried.
Common problems with oil fill and vent pipes DO NOT include
a. leaks.
b. oversizing.
c. missing caps.
d. abandonment.
b. It isn’t common for, nor would it be a problem if, oil fill and vent pipes were oversized.
Oil supply lines that carry the oil from the tank to the burner are typically
a. copper.
b. exposed along the floor or wall surface.
c. 1-inch diameter.
d. never more than 15 feet long.
a. Oil supply lines are typically copper, although they can be steel or brass as well.
All of the following are common oil supply line problems EXCEPT
a. leaks.
b. corrosion or mechanical damage.
c. undersizing.
d. excess elevation changes.
d. Excessive elevation change is not a common oil supply line problem. A fuel filter is needed in this arrangement.
Oil flows from an above-ground exterior tank, through a 2-inch pipe into the basement. Here it passes a shutoff valve and a union. The 3/8-inch copper line starts here and runs to the burner. The part missing here is a
a. fuel filter.
b. fuel pressure reducer.
c. pump to increase fuel pressure in the exterior line.
d. manifold to allow oil to be drawn off for other burners.
a. A fuel filter is needed here.
Which is NOT a common oil filter problem?
a. Leaking filter
b. Dirt
c. Missing
d. Oversizing
d. It is not common for an oil filter to be oversized.
Which of the following is NOT a cause of inadequate combustion air?
a. The water heater is in a small enclosure.
b. The house is extremely airtight.
c. There are several other pieces of equipment exhausting air from the house.
d. An air vent to the outdoors from the water heater enclosure.
d. A vent to the outdoors from a water heater enclosure does not cause inadequate combustion air. It might solve a combustion air problem.
All of the following are common venting problems on gas and oil water heaters EXCEPT
a. rust.
b. poor slope.
c. a vent connector that is too long.
d. vent connector manifolds with vent connector from furnace.
d. A vent connector from a water heater which manifolds with a furnace vent connector is a common arrangement and is not necessarily a problem.
The required clearance from combustibles for a single-wall vent connector on a gas water heater is
a. one inch.
b. two inches.
c. six inches.
d. nine inches.
c. A six-inch clearance is required from a single-wall vent connector from a gas water heater to combustible materials.
Vent connectors from conventional gas water heaters are commonly
a. corrugated.
b. aluminum.
c. B-vents.
d. L-vents .
b. Vent connectors from conventional gas water heater are commonly aluminum.
The function of a draft hood on a gas fired water heater is to
a. add air to the venting system to maintain chimney draft.
b. provide combustion air.
c. prevent the burner from competing with the furnace for combustion air.
d. prevent flame rollout at the burner.
a. Draft hoods add air to the venting system in order to maintain appropriate chimney draft.
Which of the following is not a common problem with oil fill and vent pipes on an oil storage tank?
a. Leaks
b. Abandoned tank with pipes not sealed
c. Damage or corrosion
d. A gooseneck on the vent pipe
d. A gooseneck on a vent pipe is not a problem on an oil fill and vent system
All of the following are common problems with oil burners EXCEPT
a. draft hood obstruction.
b. inoperativeness.
c. incomplete combustion.
d. excess proximity to combustibles.
a. Oil burners do not have draft hoods.
Refractories on oil burners
a. are typically located at the top of a water heater.
b. can be completely inspected during a home inspection.
c. may be masonry or ceramic fiber.
d. are located above the burner.
c. Refractories on oil burners may be masonry or ceramic fiber.
If the vent length on a gas-fired water heater is too long, then
a. the cost of the system is too high.
b. combustible clearances have to be increased.
c. there is a possibility of poor drafting and spillage of combustion products.
d. it may require supports at more frequent intervals.
c. If the vent length is too long, there is the possibility of poor drafting an spillage of combustion products on gas-fired or oil-fired water heaters.
Vent connectors on oil-fired water heaters
a. should extend 2 inches into the flue of a masonry chimney.
b. should enter a masonry chimney below a vent for a furnace or boiler.
c. should reduce in size to accelerate the exhaust products before it joins a masonrychimney.
d. are prone to corrosion along the bottom.
d. Vent connectors on oil-fired water heaters are prone to corrosion along the bottom.
Which of the following statements about electric water heaters is NOT TRUE?
a. They usually have a larger storage capacity than gas or oil tanks.
b. They have a slow recovery rate.
c. They sometimes have an energy cut out and pressure-relief valve.
d. They do not require a sacrificial anode.
d. Electric water heaters do require a sacrificial anode.
Which of the following statements about leaking water heaters is NOT TRUE?
a. Water heaters often leak at the bottom first.
b. The leaks are never a result of rusting.
c. The life expectancy of a water heater is less than that of a boiler.
d. The temperature/pressure-relief valve or drain valve may be leaking.
b. Leaks are often a result of rusting.
Gas-fired water heaters
a. can typically be installed on combustible floors, including carpeting.
b. usually require 36 inches of combustible clearance around and above the water heaters.
c. do not have any insulation in the tank walls.
d. should not be installed in bedrooms or bedroom closets.
d. Gas-fired water heaters should not be installed in bedrooms or bedroom closets.
Which of the following statements about temperature/pressure-relief valves is NOT TRUE?
a. Temperature/pressure-relief valves protect against steam explosions.
b. Temperature/pressure-relief valves shut off the water heater if the temperature exceeds210°F.
c. Temperature/pressure-relief valves should be connected to a discharge tube.
d. The Btu rating of the temperature/pressure relief valve should be at least as big as the water heater Btu rating.
b. Temperature and pressure-relief valves do not shut off the water heater. They simply allow water to discharge through the valve and discharge tube.
Which of the following statements about water heater discharge tubes for temperature/pressure relief valves is NOT TRUE?
a. The tubes cannot be plastic.
b. The tubes cannot have any shutoff valves.
c. The tubes have to extend 6–12 inches above the floor or, outdoors, 6-24 inches above grade.
d. The tube cannot have threads, fittings or caps on the end.
a. Discharge tubes on water heaters can be plastic.
Which of the following is NOT a problem with water heaters?
a. There is no isolating valve on the cold water inlet.
b. The tank is leaking.
c. There is no isolating valve on the hot water outlet.
d. The hot and cold water piping are reversed.
c. An isolating valve on the hot water outlet is not required or typically provided.
Circulating hot water systems
a. eliminate the wait for hot water after long, idle periods.
b. require no additional piping.
c. have a pump that comes on every time water flows through the hot water system.
d. should never have a check valve in the system, because that may obstruct the flow.
a. Circulating hot water systems eliminate the wait for hot water at faucets throughout the house after long idle periods.
Which of the following is a good vent-termination location for a fan-assisted, gas-fired water heater?
a. Five feet from a mechanical air supply inlet
b. Two feet from a gas meter regulator
c. Five feet from a door or window
d. Two feet from a combustion air inlet for the furnace
c. It’s all right for a vent from a fan assisted gas water heater to discharge within five feet for a door or window.
Which of the following statements is FALSE with respect to high-efficiency, gas-fired water heaters?
a. The tanks are better insulated than conventional water heaters.
b. The seasonal efficiency is 70-80 percent.
c. The exhaust gas temperatures are 100°F to 150°F.
d. They are condensing systems.
b. The seasonal efficiency of a high-efficiency gas water heater is more than 70-80 percent.
Which of the following statements about combination domestic hot water and space heating systems is FALSE?
a. They cannot be used with a radiant piping, heat-distribution system.
b. Potable water is passed through a coil in an air handler with a duct system.
c. Electric water heaters are not typically used in this application.
d. The pump may operate even during nonheating seasons to prevent stagnant water accumulations.
a. Combination hot water and space heating systems can have radiant piping-distribution systems.
A tempering valve may be needed on a combination domestic hot water and space heating system. The tempering valve
a. mixes cool water with the hot water before sending the water to a fan coil.
b. raises the temperature of the domestic hot water delivered to the house.
c. reduces the temperature of the water to the domestic hot water side.
d. protects people from scalding when bleeding radiators or radiant piping systems.
c. The tempering valve on a hot water system reduces the temperature of the water to the domestic hot water side.
Which of the following is a common problem with combination heating systems?
a. Inadequate combustion air
b. Inadequate heat and/or hot water
c. Excess pressure at faucets
d. Increased fuel consumption and cost
b. Inadequate heat and/or hot water is a common problem with combination heating systems.
Which of the following statements is true of tankless coils?
a. Tankless coils have a small, high-output burner.
b. The domestic boiler is left idle during the summer months.
c. No domestic water heater and tank are necessary.
d. These coils take up considerable space in a home.
c. No domestic water heater and tank are necessary if a tankless coil is used to provide domestic hot water.
Which of the following is NOT a drawback to tankless coils?
a. A tempering valve is usually necessary.
b. Leaking coils can damage the house boiler.
c. These coils are prone to clogging with scale and rust.
d. A separate pump is needed for the coil.
d. A separate pump is not needed with tankless coils.
A side-arm heater
a. is a variation on a tankless coil.
b. is added to the side of a domestic water heater.
c. is typically located at each fixture requiring hot water.
d. has a high-efficiency oil burner.
a. A side-arm heater is a variation on a tankless coil.
Which of the following is NOT an advantage of combination systems?
a. There is only one combustion appliance, rather than two.
b. It can be a high-efficiency system.
c. They make use of the domestic hot water in the tank, which is kept at the ready anyway.
d. These systems are typically oversized for both heating and domestic hot water, so there is a lot of capacity.
d. Combination systems are usually not over sized for heating and/or hot water usage.
Venting arrangements on high-efficiency domestic water heaters typically include all of the following EXCEPT
a. CPVC or PVC vent piping.
b. sidewall venting arrangements.
c. exhaust gas temperatures of 350°F-400°F.
d. condensate handling systems.
c. High-efficiency domestic water heaters have exhaust gas temperatures well below 350°-400° Fahrenheit.
A pressure switch on a power vented water heater
a. operates the blower if air pressure is too low.
b. provides adequate combustion air
.c. senses excess water pressure in the system.
d. verifies that the blower has started.
d. A pressure switch on a power-vented water heater verifies that the blower has started.
Common problems with temperature/pressure relief valves on water heaters include all of the following EXCEPT
a. a missing.
b. a missing discharge tube.
c. a discharge tube dripping or leaking.
d. a discharge tube made of copper.
d. Common problems with temperature pressure-relief valves do not include copper discharge tubes. These are acceptable.
Common problems for pumps with hot water circulating systems include all of the following EXCEPT
a. inoperativeness.·
b. leakage.
c. excess noise or vibration.
d. control by an aquastat.
d. It is acceptable for a hot water circulating system to be controlled by an aquastat.
Where two water heaters are installed in a single house
a. they must always be installed in the same area.
b. they are typically installed in series.
c. the upstream unit is typically smaller than the downstream unit.
d. parallel systems should have similar pipe lengths to each water heater.
d. Where two water heaters are installed in a single home, parallel systems should have similar pipe lengths for each water heater.
An energy cutoff in a water heater replaces
a. the thermostat.
b. the temperature function of the TPR valve.
c. the barometric damper.
d. the thermocouple or flame sensor.
b. The energy cut-off in a water heater replaces the temperature function of the temperature/pressure-relief valve.
Each temperature/pressure-relief valve shall have a
a. discharge tube no longer than 30 inches.
b. trapped discharge tube.
c. Full-size discharge tube extended to a safe location.
d. reducing fitting and threaded end on the discharge tube.
c. Each temperature/pressure-relief valve must have a full-size discharge tube extended to a safe location.
All gas water heaters require
a. a venting system for exhaust product.
b. enclosed water supply pipes.
c. temperature/pressure-relief valves.
d. 12 inches of elevation off of the floor in a garage.
a. All gas-fired water heaters require a venting system for exhaust products.
All gas meters should be preceded by a
a. bypass connection.
b. shutoff valve.
c. drip leg.
d. union connection.
b. All gas meters should be preceded by a shut-off valve.
Conventional gas-fired water heaters may be installed in
a. bedrooms.
b. bathrooms.
c. kitchens.
d. All of the above
c. Conventional gas-fired water heaters may be installed in a kitchen.