Cellar or basement floor drains shall connect
into a deep seal trap so constructed that it can be readily cleaned,
and of a size not less than three inches in diameter. When subject
to backflow of back pressure, such drains may be equipped with an
adequate backwater valve or a standpipe no less than two inches in
diameter, and same to be four feet above cellar floor.
All direct-connected hydraulic elevators, lifts
or pressure machines shall be provided with an intermediate tank of
sufficient capacity as to discharge its waste without pressure into
any sewer, drain, soil or waste pipe. Such tanks shall be trapped
and, where there is danger of back pressure from sewer, there shall
be placed on its outlet side a sewer or backwater valve.
Where the minimum size house drain is allowed,
the trap for the floor drain must connect into the main drain at least
five feet from the soil pipe, or may be connected into a three-inch
drain that receives only the waste of tray and sink.
The required sizes of storm-water house drains
and other lateral storm drains shall be determined on the basis of
the total drained area in horizontal projection in accordance with
the following table, and in no case shall be less than three inches:
Storm Systems Only
|
---|
Diameter of Pipe
(inches)
|
Maximum Drained Roof Area in Square Feet
(slope 1/8 inch fall to 1 foot)
|
---|
3
|
865
|
4
|
1,860
|
5
|
3,325
|
6
|
5,315
|
8
|
11,115
|
10
|
19,530
|
12
|
31,200
|
14
|
42,600
|
All cast-iron pipe and fittings for underground
drainage use shall be coated with asphaltum or coal-tar pitch.