(a) 
Traps shall be placed as near the fixture as possible and in no case shall a trap be more than 2' (developed length) from the waste outlet of the fixture. All traps shall have at least a 1-1/2" and not more than a 4" seal. Traps placed below the floor shall have a brass trap screw for cleaning which shall be accessible. The interior walls of cast brass traps, unless machined, shall have been sand blasted so that there are no sharp points or obstructions in the trap. All traps shall be rigidly supported and set true with respect to their water level and shall be located to protect the trap seal. Traps which depend upon the action of movable parts to form a seal shall not be used. Traps which depend upon concealed interior partitions to form a seal or which have interior partitions, which in case of defect will permit the passage of sewer air shall not be used.
(b) 
All closet, urinal, slop sink, floor drain and shower traps shall have a visible trap seal.
(1965 Code, sec. 15-160)
(a) 
Each bathtub shall be provided with an extra heavy lead drum trap, 4" x 8" or larger except when the “durham” system is used, drum traps may be of cast iron or brass. Traps on bathtubs shall be placed in such a manner that the cleanout shall be accessible. The outlet from a drum trap shall be wiped into the trap in such a position that the waste outlet shall be water sealed to a depth not less than 2-1/2" and not more than 4" and not more than 6" laterally from the trap. The inlet shall enter below that water level in the drum trap. Drum traps serving bathtubs shall not connect to the lead bend or lead ferrules under any water closets. When drum traps are installed on a continuous waste and vent system, the waste line may be connected using a 4" x 2" Y on a horizontal between lead bend and stack, or a 2" side outlet fitting similar to “Wisconsin sanitary tee” commonly known as “crowfoot fittings,” or by using separate fittings such as 4" x 2" sanitary tee. When this construction is used, the drum traps shall be ventilated through the waste fitting and the outlet of such fitting shall not be set below the dip of the trap. Inlet and outlet of drum trap shall not be less than 1-1/2" in diameter. A distance not to exceed 3-1/2' developed length will be permitted between trap and point of entrance to waste line, and the distance from the top of the solder nipple to the drum trap on inlet side of trap shall not exceed 2' of developed length. This construction may be used only where there are no fixtures on floor above wasting into the main soil or waste stack.
(b) 
Traps for lavatories shall be cast brass traps with seal not less than 1-1/2" or more than 3" in depth and with a discharge capacity equal to that of a 1-1/4" pipe, so constructed as to provide access in case of stoppage.
(c) 
The connection between drainage pipes and water closets, floor outlet service sinks, pedestal urinals, and earthenware trap standard fixtures, shall be made by means of brass or hard lead floor flanges soldered or lead welded to the lead bend or at least six inches of lead pipe. C.I. stubs or bends with C.I. calk-on type closet flanges may be used in concrete slab floors constructed on the ground. The connection shall be bolted to the fixture by means of red brass bolts with an approved gasket, washer, setting compound or white lead putty between the fixture and the connection. No commercial putty shall be used. The floor flange shall be set on an approved firm base. The lead connection shall be independent connection for fixture only. All other waste pipes shall discharge into a separate fitting. In wooden joist construction the distance between the wiped joint on the lead stub serving the fixture shall not be less than 4" from the underside of the floor.
(d) 
Traps for kitchen sinks shall be extra heavy lead or cast brass traps with seal not less than 1-1/2" or more than 3" in depth and with a discharge capacity equal to that of a 1-1/2" pipe.
(e) 
Traps for urinals shall be cast iron or cast brass traps with seal not less than 1-1/2" or more than 3" in depth and with a discharge capacity equal to that of a 1-1/2" pipe. Urinals with integral traps will be permitted.
(f) 
Traps for lavatories, sinks, urinals, or other fixtures which connect with screw pipe, as provided for herein, shall be cast brass and of the New York or Los Angeles pattern.
(g) 
Traps for wash trays shall be drum traps of no smaller dimensions than 4" x 8" extra heavy lead and one trap may be used for a battery of three trays and the trap outlet shall not be less than 2" in diameter. Traps for single wash trays may be extra heavy lead or cast brass P traps with seal not less than 1-1/2" or more than 3" in depth and with a discharge capacity equal to that of a 1-1/2" pipe. Wash trays with a partition forming two compartments with one waste outlet will be considered as a single wash tray.
(1965 Code, sec. 15-161)
(a) 
Each shower bath shall be provided with trap of cast iron, brass or lead with water seal of not less than 2" or more than 4". Inlet and outlet of this trap shall not be less than 2" in diameter. Showers installed independent of shower heads over bathtubs shall be wasted through a double drainage floor drain appliance as made by the various manufacturers, and approved by the plumbing inspector. Drilling of the brass strainer will not be permitted. Waste shall connect with either vertical stack or horizontal house drain independent of all other fixtures, and in no case shall be connected to lead bend or lead ferrule serving water closets. When 2" P traps are used under showers in order to keep from cutting the floor joist, the extension from trap to strainer shall be of cast iron or brass and the distance from floor line to trap shall not exceed 2', and the distance from water seal to point of entrance on vertical or horizontal connection or continuous waste shall not exceed 5'. Beyond this limit, traps shall be revented.
(b) 
Wherever built-up shower baths are installed except those constructed on concrete slabs directly on the earth, the base of the shower stalls shall be lined with sheet lead and weighing not less than four pounds to the square foot. Lead shower pans shall be protected on both upper and lower sides by coating with asphalt and application of 30 pounds asphalt felt over such coating on both sides of pan. The sheet lead shall be turned up on all sides to a height of not less than 6". Base and walls of shower stall shall be of nonabsorbent materials and impervious to moisture.
(c) 
When shower baths are installed in manufacturing establishments, shop and engine or boiler rooms in basements or if the floors in such places are constructed on the ground using concrete or tile, then the double drainage fixture and lead pan need not be used. Cast iron combination P trap with strainer may be used with wastes and vents in such business establishments.
(d) 
Prefabricated shower stalls with metal walls and enameled metal, stainless steel or terrazzo receptor may be installed on the ground floor of residential buildings only. Said stalls installed in residential buildings above the ground floor shall have terrazzo receptors. Shower walls and receptor shall be connected with watertight joints in such installations.
(1965 Code, sec. 15-162)
(a) 
Bar sink wastes shall not be smaller than 2" in diameter and the discharge shall be intercepted by a cast iron grease trap having dimensions not less than 19" x 11-1/2" x 10" deep or equal capacity, when bar connections do not exceed three openings including those from floor drain and iceboxes. Soda fountain wastes and a combination of from 4 to 12 bar sinks or waste openings including floor drains shall have a waste not smaller than 3" in diameter, and the grease trap shall not be less than 20" in diameter by 20" deep or equal capacity, and 2" P traps shall be installed directly under the bar sink opening. The bar sink openings shall be permanently connected to the P traps. When a combination of waste openings from a soda fountain exceed 12 and does not exceed 36, the drain shall be 4" in diameter and shall discharge into a grease trap 30" in diameter by 30" deep or equal capacity.
(b) 
A floor constructed of concrete, terrazzo or other impervious material shall be installed from front line of the counter to the rear line of the back bar for entire length of walkway. A floor drain not less than 2" in diameter shall be installed for every 100 square feet of this area but the distance between floor drains shall not exceed 15'. Horizontal pipes installed under bars and fountains shall be located at least 5" above the floor. All iceboxes or refrigerator drains shall waste on indirect connection to floor drains or open fixtures.
(c) 
When a grease trap is located below finish floor grade, a cast iron frame and cover shall be placed in the finished floor directly over grease trap so it will be accessible for cleaning. Grease traps shall be revented although they are not classed as fixtures. Each fixture and appliance connected to a grease trap shall be trapped and each fixture and appliance so trapped shall be listed as a separate fixture, and subject to inspection and permit fees as such. A vent shall be installed at the farthest point from the grease trap on waste line and this vent shall be equal in size to the waste line. Where the bar or fountain is 30' from the grease trap an additional vent not less than 1/2 the diameter of the waste line shall be installed in front of the first waste opening. These vents shall not be laid horizontally more than 6' from the waste line to the vertical rise. A cleanout shall be installed at base of said vertical vents in an accessible location.
(d) 
The vents may be extended through the roof separately or they may be connected together provided the connection is located 1' above water level of the fixture or they may be connected to any sanitary vent of sufficient size. A cleanout shall be installed flush with the floor at the end of each waste line and this cleanout shall be equal in size to that of the waste line. The waste line between the grease trap and the vents shall be of uniform size. A blow-off or catch basin will not be accepted in lieu of a grease trap.
(1965 Code, sec. 15-163)
(a) 
Waste pipes from kitchen sinks in any hotel, restaurant, boardinghouse, school and all other public places serving food or where drinks are prepared for sale and are served on the premises shall discharge into a grease interceptor (trap) made of cast iron with a removable cover. One sink, or from one compartment to four compartment sinks, shall waste through a grease interceptor (trap) of not smaller size than 19" x 11-1/2" x 10" deep or equal capacity.
(b) 
Sinks shall be constructed of corrosion-resistant metal, not lighter than 18 gauge, and fabricated so that joints are smooth and easily cleanable. Sinks for hand dish washing operations shall be built with at least three compartments and the minimum size for each compartment shall be 14" x 14" x 12" deep (or equal capacity so that no side shall be less than 12"). This minimum size three compartment sink will not be suitable for a place washing large quantities of dishes. A smaller compartment for use as a waste sink may be constructed with this three compartment sink. When it is desired to separate the glass and dish washing procedure another compartment may be added.
(c) 
All the fixtures and floor drains in hotels, kitchens, restaurants, cafeterias, drive-ins, hospitals, schools and other public places where food is prepared or cooked may waste into one grease interceptor that is vented as heretofore specified and each fixture wasting into this grease interceptor shall be trapped and vented as specified in this article. To determine the proper size of the waste lines to this grease interceptor the fixture unit valve as specified in fixture unit table of this division shall be used. The total number of fixture units wasting into the grease interceptor shall determine the proper size waste line and the inlet and outlet of the grease interceptor shall not be smaller than the line wasting into it.
(d) 
For calculating the required sizes of grease interceptors the rate of discharge from each fixture connected to the interceptor shall be based upon the rates shown in the fixture unit table as set forth in this division. The grease retaining capacity of each grease interceptor, in pounds of grease, shall be equal to twice the rate of flow capacity in gallons per minute of wastewater so that the interceptor shall remove and retain 90% of the grease discharged into it up to its required capacity of accumulated grease.
(e) 
Unless otherwise approved by the chief plumbing inspector, grease interceptors shall separate grease while it is in the liquid state; that is, separation shall be accomplished by differential gravity methods, assuming temperatures of waste at 150 degrees F. and a rate of rise of grease at 1.05' per second reduced to 0.025' per second to allow for turbulence. The chief plumbing inspector shall establish detailed formulas for further determining the effectiveness of grease interceptors submitted for approval under these regulations and shall prepare and maintain a list of interceptors which are approved.
(f) 
All grease interceptors shall be maintained by the owner at his expense, in continuously efficient operation at all times. Such grease interceptors shall be located on the premises served.
(1965 Code, sec. 15-165)