A.
Every trap shall be self-cleaning. Traps for bathtubs,
lavatories, sinks and other similar fixtures shall be of lead, brass,
cast iron or of malleable iron galvanized or porcelain enameled inside.
Galvanized or porcelain-enameled traps shall be extra heavy and shall
have a full-bore smooth interior waterway with threads tapped out
of solid metal.
B.
The minimum size (nominal inside diameter) of the
trap and waste branch for a given fixture shall be not less than that
shown in Table No. 1 given below and to which reference is hereby
made.
|
Table No. I
| ||
|---|---|---|
|
Kind of Fixture
(inches)
|
Size of Trap and Branch
| |
|
Bathtubs
|
1 1/2
| |
|
Laundry trays
|
1 1/2
| |
|
Sinks, kitchen, residence
|
1 1/2
| |
|
Sinks, hotel or public
|
2
| |
|
Sinks, small pantry or bar, or dishwasher
|
1 1/2
| |
|
Sinks, slop, any type
|
3
| |
|
Shower stalls
|
2
| |
|
Urinals, troughs, stall or lip
|
2
| |
|
Urinals, pedestal
|
3
| |
|
Washbasin
|
1 1/2
| |
|
Water closet
|
3
| |
|
Other fixtures
|
1 1/2 minimum
| |
No form of trap which depends for its seal upon
the action of movable parts or concealed interior partitions shall
be used for fixtures.
Each fixture shall be separately trapped by
a water-seal trap placed as near to the fixtures as possible, except
that a set of not more than three laundry trays or a set of two laundry
trays and one sink may connect with a single trap, provided that the
trap is placed centrally and the branches connect into the trap seal
at an angle of not more than 60° to the vertical arm. No fixtures
shall be double-trapped behind the house trap.
Each fixture trap shall have a water seal of
not less than 1 1/2 inches and not more than four inches, except
grease traps.
All traps shall be set true with seals and protected
from frost and evaporation.
The bodies of cleanout ferrules shall be made
of standard pipe sizes and material known as "extra heavy" and with
heavy brass screw plugs, with a solid square or hexagon nut not less
than one inch high and 1 1/4 inches in width.
A cleanout, easily accessible, shall be provided
at the foot of each vertical waste or soil stack. There shall be at
least two cleanouts in the house drain, one at or near the base of
a stack and the other, with full-size Y-branch, inside the wall near
the connection between the house drain and house sewer.
All underground traps and cleanouts of a building,
except where cleanouts are flush with the floor, and all exterior
underground traps shall be made accessible by manholes with heavy
iron, concrete or flagstone covers.
