Storm Drains
You need to know this to size roof drains
Total square footage
The pitch of 3" pipe is
1/4" per foot
What is a crown vent
A vent installed within two pipe diameters of the trap weir
What is the critical level of a vacuum breaker
6" above the fixture being served
what is the formula for finding the capacity in gallons in a cylindrical tank when given the dimensions in inches
D2" X Length" X .0034 = Gal
Semi continuous draining on a roof, computes to this
1 G.P.M equals 24 Square feet
When your draining 1 toilet to a sewage pump, what is the discharge rate
20 G.P.M
All building drains within a structure shall, at minimum have at least one full size main stack vent or a vent stack no less than
3" in diameter
What is the maximum temperature for hot water in a building
130 degrees
How many gallons of water is in a cubic foot
7.5 gallons
You need to trap a roof drain when this takes place
Connects to a sewer
The independent laundry main drain shall connect to the building drain
a minimum of 40 pipe diameters upstream and downstream of any soil or waste stack.
The vent extension through a roof shall be no less than and shall extend to a point
2" in diameter and extend 18" - 24"
The maximum distance of a hot water line before a recirculation line is needed
75 feet
How many branch intervals can you have before you'll need a relief vent
10 branch intervals
The minimum and maximum from the ground a secondary roof drain needs to drain
18" - 60"
Not less than a 1½ inch branch waste or waste outlet shall be provided to receive the fixture drain from a kitchen sink, which shall connect
independently to the sanitary drainage system.
Where frost closure is likely to occur, each vent extension through a roof shall be at least
3" in diameter
Whenever water pressure from the street main, service, or other source of supply is insufficient to provide flow pressures at fixture outlets as required under 248 CMR 10.14(2)(c)
A booster pump and pressure tank
When installing storm drains in a parking garage what is needed for protection
recessed into the wall and guard rails
Roof drain assemblies for use on sun decks, parking decks, and similar areas, normally serviced and maintained, may be
level with the deck and shall have an available inlet area not less than two times the area of the conductor to which the drain is connected.
Fixture unit values for continuous or semi-continuous flow into a building sanitary drainage system, such as from a waste pump, sewage ejector pump, or similar device that discharges sewage waste shall be computed on the basis of
two fixture units for each gallon per minute of flow
Piping not to serve as a wet vent would include
1. Kitchen sink
2. Garbage disposal
3. Dishwasher
4. Laundry
5. Any sink used for culinary purposes
What is the flow pressure of a kitchen sink (residential)
8 P.S.I
What is needed on all risers that feed a second floor with multiple fixtures
A full port ball valve with drain valves upstream