Chapter 2 - Planning Plumbing Projects Flashcards
How early in advance should you choose your material, equipment, and personal requirements at the company level?
30 days in advance.
How early in advance should you choose material, equipment, and personal requirements at the job supervisor level?
Two weeks in advance.
How early in advance should you choose material, equipment, and personal requirements at the crew leader level?
No less than one week in advance.
What is a key aspect to lead times and material availability?
Location of the project.
How many days do you have to make a change to the schedule when the crew has arrived on the job?
You generally have 45 days.
What are good supervisors responsible for?
Ensuring equipment, material, tools, and other facilities are on the job needed.
What books she is you use for planning, estimating, and sizing plumbing systems?
The national standard plumbing code, military specifications, job specifications.
What type of protection does threaded pipe that is underground require?
Coal tar protection.
How far apart should water service lines and waste lines be from each other?
Not less than 6 feet apart horizontally.
What should water service lines and waste lines be placed on inside of the trench?
Either undisturbed or compacted earth.
How should sanitary drainage and storm building drains be placed inside of the ground?
They should be placed in one trench side-by-side.
What type of piping material should you use when a building sewer or building drain is installed and filter or unstable ground?
Cast iron soil piping.
When may you use nonmetallic drains?
When laid on an approved continuous supporting system.
Why should you pay special attention to joints in the piping system?
So that routes do not grow into the piping.
What depth should you bury the piping?
Below the frost line.
What should you in case the piping in when laying under roadways?
You should in case the piping with concrete or sleeve it with metallic material.
If you have to install the building sewer line in the water service line in the same trench where should you place the water service line inside of that trench?
You need to make sure that the bottom of that water pipe is at least 12 inches above the top of the sewer line off to the side laying on a shelf.
After meeting the requirements for installing the water service line with the building sewer line what test should you do to test the building sewer line?
You should test the building sewer line with a 10 foot out of water or an equivalent test.
What decides the flow velocity of the liquid within the pipe?
The slope, pitch, grade, or drop per foot.
How low should you slope piping 3 inches or less in diameter?
No less than a quarter inch per foot.
How should you slope piping that is 4 inches or larger?
No less than an 8th inch per foot.
How does piping benefit from proper sloping?
It allows the velocity of not less than 2 ft./s and keeps the pipe free from fouling.
What is the minimum slope inch per foot for piping that is 2 1/2” or less?
1/4
What is the minimum slope inch per foot for piping that is 3 to 6 inches?
An 8th inch
What is the minimum slope inch per foot for piping that is 8 inches or larger?
1/16th
Hey slope drop of more than a quarter inch per foot is bad for piping systems, why?
Slope drops more than a quarter inch per foot make a siphonage of the trap seal.
What increases the caring capacity of a drain?
Higher velocity’s or greater drop her foot.
What makes an effective technical advisor?
Self-study combined with on the job training and field experience.
What is the minimum allowable size of typing for building drains?
3 inches but plumbing codes or ordinances require 4 inch pipe as a minimum.
Why is going beyond the size of piping that you need for building drains not the best action to take?
The scoring action from liquid and solid waste is lost when the size of the drain is increased above the necessary size.
Using too large of a pipe and building drains causes what?
It causes the flow to be shallow and slow and solids settle at the bottom which cost stoppages in line.
When using the optimum size piping for building drains how should it flow?
The optimum size piping for building drains should flow half-full under normal use.
Why does the optimum piping of building drains flow half-full?
It creates an efficient, natural scouring action and still allows capacity for peak loads.
What is the standard method used in determining the size of building drains?
It’s the drainage fixture unit system.
How do you calculate the total volume of liquid waste?
By multiplying the number and type of fixtures by the unit value.
I.E. 20WC x 6 = 120 total discharge
Minimum pipe size = 4”
Minimum stack size = 4”
How would you determine what size piping and slope you would need for draining all of the fixtures in a building?
You take the total drainage fixture unit values and look up the maximum loads for the horizontal drains which will give you the size of the piping that you need. You can find these in table 2-5 of UT advanced.
When copper tubing is used for building drain lines what size will it be as opposed to what is shown on the table?
Copper tubing may be one size smaller than what it says on the table.
Should the size of building drainage lines ever decrease in the direction of flow?
The sizes should never decrease in the direction of flow.
How should you a lemonade any dead ends of the stack?
Dead ends of the stack should have plugged fittings.
What is a stack?
It’s a vertical line of soil or waste piping.
What is the difference between a waste stack and a soil stack?
A waste stack carries liquid waste and a soil stack carries liquid waste and human excrement.
Do most buildings have separate soil and we stacks?
No buildings mostly have a single stack known as the soil stack or the soil and waste deck.
What are soil stacks usually made of?
Cast-iron piping with caulked joints. They may be made of galvanize steel or copper tubing.
How should you size a stack?
In the same way that you size of building sewer. By taking the total drainage fixture unit value and looking at table 2-6 in UT Adavanced
When should a soil and we stack be smaller than the largest horizontal branch connected?
Never.
Should a 4 x 3 water closet connection be considered as a reduction in pipe size?
No it should not.
If there is an offset in the vertical stack when is it okay to size it as a straight vertical stack?
When the offset has a change in direction of 45° or less.
When should a relief vent in the drainage piping be installed?
When a horizontal branch connects to the stack within 2 feet above or below the offset.
How should a stack with an offset greater than 45° be sized at the top portion that is above the offset?
The stack above the offset should be sized for a regular stack based on the number of drainage fixture units above the offset.
How should a stack with an offset greater than 45° be sized at the actual offset portion itself?
the offset should be sized for the building drain.
How should a stack with an offset greater than 45° be sized at the portion below the offset?
The stack below the offset should be sized to the offset or the total number of drainage fixtures in the entire stack which ever is larger.
If you have an offset in the stack that is greater than 45° what should you install to provide adequate air to an area in the waste piping that might not get much air?
You should install a relief vent for the offset.
What is the rule of thumb for connecting a horizontal branch or fixture to the stack that has an offset that is greater than 45°?
You never connect the horizontal branch or fixture to the stack within 2 feet above or below the offset.
How big are closet bends in diameter if made of cast iron, steel or PVC?
The closet bend is three or 4 inches in diameter.
How big is the closet bend in diameter if it is made of copper?
3 inches.
How can you keep lavatory drainage optimal?
You can keep hair from stopping the drain’s by using a minimum number of fittings and by eliminating long horizontal runs.
What is the minimum pipe size for lavatory wastes?
1 1/4 inches but one and a half inches works better.
What size of the waste pipe should be used for wall-mounted urinals?
1 1/2 inches.
What size waist pipe should be used for pedestal siphon jet urinals?
3 inches.
What material is usually 2 inches in diameter for shower waste piping?
Cast iron or steel.
What material is usually one and a half inches in diameter for shower waste piping?
Copper.
What size steel or PVC waste piping must be used for domestic kitchen sink that has no garbage disposal?
1 1/2”
What size steel or PVC waste piping is used for a domestic kitchen sink that has a garbage disposal?
A minimum of 2 inches.
What is another name for service sinks?
Slop sinks.
What are the two styles of slop sinks?
Trap to wall
Trap to floor
What is the difference between a trap to wall type slop sink and a trap to floor type slop sink?
A trap to wall type requires 2 inch or 3 inch waste pipes
A trap to floor requires a 3 inch waste pipe
If copper tubing is used for trap to wall type and trap to floor type waste piping for slop sinks what sizing is permitted?
A one size reduction is allowed.
What are scullery sinks used for?
Washing large pots and pans and for general scouring purposes.
What size waste piping is necessary for scullery sinks?
2” waste pipe because of the grease that passes through them.
What size waste piping should you use for drinking fountains?
1 1/4 inch waste piping. And indirect drain should be used.
How many gallons per day can a permanent residents person contribute to the sewer?
100 gallons per day.
How many gallons can a person in the industrial area per eight hour period contribute?
30 gallons per person.
When determining the size of a sewer what factors are considered?
The average rate and the extreme peak rate of flow.
What is the typical sewer peak flow for small areas?
Six
What is the typical sewer peak flow for large areas?
1.5
How would you go about getting the design flow for a sewer system?
By adding peak flow to the allowance for infiltration of subsurface water.
What is a typical infiltration allowance for a sewer system?
500 gallons per inch of pipe diameter, per mile of sewer per day.
When would additional capacity to provide for population increase being clued into areas?
It would be included for areas that are likely to continue to develop.
What percentage would you go over the initial sewer requirements if an area is projected to develop?
25% additional capacity over the initial requirements is advisable.
What is each length of pipe from one manhole to the next sized to carry?
It is size to carry design flow at the upper demands of the system.
What are the typical minimum sizes for houses, and industrial waste sewers?
6 inch pipes.
What are the typical minimum sizes for all other sewers that do not serve houses or industrial waste?
8 inch pipes.
How would you allow for expansion and sewer lines?
By selecting a pipe size that will carry the design flow when the pipe is half-full.
Which pipe is smoother asbestos cement pipe or concrete pipe?
Asbestos cement pipe.
What will carry a greater flow on the inside of the pipe, if the pipe is smooth or if the pipe is rough?
A smoother pipe will carry a greater flow.
What does a 1% slope mean?
It means 1 foot of fall in 100 foot length of pipe. About an 8th inch per foot.
What does a 0.5% slope mean?
It means 6 inches of fall and 100 feet it’s about a 16th inch per foot.
Rather than inches what else may slope be expressed in?
Percentage.
When a slope in a sewer passes through each manhole how should the slope remain?
Constant.
If you put a big pipe and a small pipe next to each other with a drastically decreased depth of flow which pipe will flow faster?
Both pipes might float the same because of the grade, therefore flow velocity is limited by the rate of flow.
What are the typical minimum flow velocities for a sewer line?
2 ft./s at the filled design flow and 1.6 ft./s at the average rate of flow.
If the velocity is too high inside of a sewer line what will that do to the pipe?
It will erode the pipe.
What is the typical maximum velocity for concrete pipe?
15 ft./s.
When should the sewer line pipe size be reduced?
Whenever better flow conditions would result.
What intervals are manholes placed in sewer lines?
Their place in intervals of 300 or 500 feet.
When should preference covers not be used In sewer lines?
They shouldn’t be used in sanitary sewer manholes because the openings would let sand grit and surface water in.
How are sewers ventilated?
Sewers are ventilated by the stacks of the building plumbing systems.
Should storm drainage systems be separate from sanitary sewer systems?
Yes whenever possible.
What type of pipe material may you use for storm drains?
The part material may be the same as the ones used for the sanitary system.
What type of piping material is used for larger storm drain systems?
Reinforced concrete pipe.
Do the joints of the storm drain sewer system need to be watertight?
No it’s not required.
If you don’t put mortar around the joints of the storm drain sewer system then what would you place next to the openings?
Washed gravel.
How much should building storm drains be graded?
A quarter inch per foot whenever possible.
What type of fittings are used when a change of direction is necessary within storm and sanitary system?
Long radius fittings.
Do cleanouts need to be installed one long radius fittings are used in storm and sanitary systems?
No.
When are manholes used in the storm and sanitary system?
Outside of buildings want to change in direction is necessary or when two or more lines are connected together.
What factors must be considered when sizing building storm drains?
Rainfall intensity, roof size, and the pitch of the roof.
Besides using a table what is another method for sizing building storm drains?
One square inch of pipe cross-sectional area for every 100 ft.² of roof area.
What is a stream of water in the pipe made of?
It’s made up of a series of layers moving at different speeds.
When water is moving at different layers inside of a pipe which layer is moving the fastest?
The center layer is moving the fastest.