No form of trap will be permitted to be used unless it has been approved by the Superintendent of Buildings and the Board of Plumbers.
No mason's cesspool, bell, pot bottle or D-trap will be permitted, nor any form of trap that is not self-cleaning nor that has an interior chamber of mechanism, nor any trap except earthenware ones that depend upon interior partitions for a seal. Backwater or tide valves will only be permitted when it can be shown to the satisfaction of the Superintendent of Buildings that their use is absolutely necessary and that they are of a type as approved by him.
Every fixture must be separately trapped by a water-sealing trap placed as close to the fixture outlet as possible, and no trap shall be placed more than two feet from any fixture.
A set of not more than three washtrays may connect with a single trap or into the trap of an adjoining sink, provided both sink and tub waste outlets are on the same side of the waste line and the sink is nearest the line. When so connected the waste pipe from the washtrays must be branched in below the water seal.
The discharge from any fixture must not pass through more than one trap before reaching the house drain.
All traps must be well supported and set true with respect to their water levels.
All fixtures other than water closets must have strong metallic strainers or bars over the outlets to prevent obstruction of the waste pipe.
All exposed or accessible traps, except water closet traps, must have brass trap screws for cleaning the trap, placed on the inlet side or below the water level.
All iron traps for house drain, yard and other drains and leaders must be running traps with manhole cleanouts of the full size of the traps, when same are less than five inches. All traps underground must be made accessible by brick manholes with proper covers.
Overflow pipes from fixtures must in all cases be connected on the inlet side of traps.
All earthenware traps must have approved heavy brass floor plates properly secured to the branch soil pipe and bolted to the trap flange, and the joint made gastight. The use of rubber washers for floor connections is prohibited. All floor flanges must be set in place and inspected before any water closet is set thereon.
No trap shall be placed at the foot of the main soil and waste pipe lines.
The sizes for traps must not be less than those in the following table:
Type of Fixture
Diameter
(inches)
Water closets
4
Slop sinks
3
Kitchen sinks
2
Washtrays
2
Urinals
2
Shower bath
2
Other fixtures
1 1/2
Area, floor and other drains
3
Every plunge bath shall be provided with a trap at least four inches in diameter, the waste line from trap to bath to be reduced to two inches in diameter and this waste to be controlled by a gate valve. Overflow pipes, if provided, must be connected on inlet side of trap. Except where an approved antisiphon trap is installed, such trap must be ventilated by a separate vent line extending above the roof, of the same size as the trap and water connection.
Every dental cuspidor must be separately trapped by a trap of at least 1 1/2 inches in diameter, which shall be vented except where an approved antisiphon is installed and placed as close to the fixture as possible. The connection between trap and cuspidor may be 3/4 inch in diameter.
A. 
Required. Grease traps shall be installed in the waste lines of restaurants, beauty parlors or any other type of business where excessive amounts of grease or soap accumulate, as determined by the Superintendent of Sanitation.
B. 
Size. The size of such grease traps shall be set by the Superintendent of Sanitation.
C. 
Installation; inspection. Installation of grease traps shall be in accord with the rules and regulations of the Department of Buildings and shall be inspected by the Inspector of Plumbing.
A. 
Prohibited generally. No plumbing fixtures, except bar sinks, soda fountains, drinking fountain or washing machines, shall be installed with an indirect waste connection to the plumbing and drainage system.
B. 
Bar sinks, soda and drinking fountains, washing machines. The waste of every bar sink, soda fountain, drinking fountain or washing machine, if not directly connected, must discharge over a properly water-supplied trapped fixture, with trap vented, unless an approved antisiphon trap is installed. The main waste lines shall be two inches in diameter, and the branches to fixtures at least 1 1/2 inches in diameter. Drinking fountains must be trapped and the waste line extended through the roof. No vent connections need be provided.
Oil separators installed in any building where volatile fluids are used must be arranged to be readily accessible. They must not receive the discharge of any water closet, rain leader, yard, court or area drain.
Oil separators, if discharged by gravity, must be connected by a Y-branch fitting to the house drain behind the house trap in such a manner that they will not interfere with the house drain and the rest of the plumbing and drainage system. Oil separators shall be connected by a Y-branch fitting on the sewer side of the house trap.
No separate running trap need be provided on the drain entering oil separators, but a separate fresh-air inlet and vent line must be provided to keep the system of drainage controlled by the oil separator entirely separate from the rest of plumbing and drainage system.
The size of fresh-air inlet required by § 162-166 shall be determined by the size of the inlet connection to the oil separator, which shall be considered the same as the term "house drain" for determining the size of all fresh-air inlets, and which shall conform to the same requirements regarding the size and arrangement of terminals for fresh-air inlets as are called for in these regulations.
Vent lines for oil separators shall conform in all respects to vent lines for plumbing fixtures, regarding the size and arrangement.
Relief pipes for oil separators of a size at least 1 1/2 inches in diameter must be provided. They may be connected to a vent line when installed as a separate system or shall be carried independently above the roof.