Chapter 10 Traps and Interceptors

Trap arm

Not more than one trap shall be permitted on a -

1, 0.75 m

___ trap may serve as a set of 3 single compartment sinks or laundry tubs of the same depth, or 3 lavatories immediately adjacent to each other with their waste outlets ___ apart and the trap is centrally located

Clotheswasher or Laundry tub

Shall not be connected to any trap of a kitchen sink.

22.5°

for trap arms 76mm in diameter and larger, a change of direction greater than ___ is required at the bend

0.6 m

The vertical distance between a fixture outlet and the trap weir shall be as short as practicable, but in no case shall the tailpiece from any fixture exceed ____ in length.

Separate trap

No food waste disposal unit shall be installed on any set of restaurant commercial or industrial sinks served by a single trap, each such food waste disposal unit shall be connected to a -

1.8 meters

The developed length between the trap of a water closet or similar fixture measured from the top of closet ring (closet flange) to inner edge of vent shall not exceed -

90 degrees.

A trap arm may change direction without the use of a cleanout when such change of direction does not exceed -

Weir of the trap

The vent pipe opening from a soil or waste pipe, except for water closets and similar fixtures, shall not be below the -

51 mm to 102 mm (2” to 4”)

Each fixture trap shall have a water seal depth of ____ to ____.

Self cleaning

Each trap, except one for an interceptor or similar device shall be -

Outlet side

No more than one approved slip joint fitting may be used on the ____ of a trap.

102 mm

No more than _____ deep except where a deeper seal is found necessary.

Backwater valve

When subject to reverse flow of sewage or liquid waste, such drains shall be equipped with an approved -

1.2 m

The horizontal distance between fixture outlet and the grease trap should not exceed _____

0.75 m

the maximum vertical tailpipe or drain between fixture outlet and the grease trap should not exceed _____

Properly vented

Each interceptor (clarifier) shall be -

Wash rack

Slab used for cleaning machinery or machine parts shall be adequately protected against storm or surface water and shall drain or discharge into an interceptor (clarifier) of an approved design for this use to separate the oil and grease before the effluent reach the public stream.

152 mm

Interceptors or clarifiers for sand and similar heavy solids shall be designed and located as to be readily accessible for cleaning and shall have a water seal of not less than

Grease trap

Is not required for individual dwelling units or for any private living quarters.

2.5 hours

What is the retention time of a Commercial kitchen waste dishwasher?

Greater

Each grease trap shall have an approved water seal of not less than 51mm in depth or the diameter of its outlet, whichever is -

610 mm

Minimum depth under the invert of the outlet pipe for sand interceptors.

Sand interceptor

Multiple floor drains may discharge into one -

0.2 square meter

The sand interceptor shall have a minimum dimension of ____ for the net free opening of the inlet section.

Outlet pipe

The invert of the inlet pipe shall be no lower than the invert of the -

50%

The outlet section shall at all times have a minimum area ___ of the inlet section for sand interceptor

0.76m or 2.5 feet

What is the standard horizontal distance of 32mm trap arm diameter?

1.07m or 3.5 feet

What is the standard horizontal distance of 38mm trap arm diameter?

1.52m or 5 feet

What is the standard horizontal distance of 51mm trap arm diameter?

1.83m or 6 feet

What is the standard horizontal distance of 76mm trap arm diameter?

3.05m or 10 feet

What is the standard horizontal distance of 102mm and larger trap arm diameter?

water-sealed trap

each plumbing fixture except ones with integral traps (like WC) shall have a ____

clotheswasher

a trap serving a laundry tub may also receive the waste from an adjacent _______

2x the diameter of trap arm

minimum developed length of trap arm

Gauge 17 B&S or 1.1mm

thickness for exposed and readily accessible drawn brass tubing trap, excluding urine

adapter

tubing trap shall be installed with a listed tubing trap _____

Common Seal P-trap

5cm (2”) deep water seal

Deep Seal P-trap

7.5cm to 10cm (3” to 4”) deep water seal

drum trap

intended for fixtures set on the floor like a bathtub, foot, and sitz bath. they are only allowed when permitted

1. "S" trap,

2. Bell trap

3. Crown vented trap

4. double-trapping

Vented traps that are prohibited.

1. stand trap

2. extra heavy

3. brass

4. low hub

5. high hub

permissible traps include

trap primer

protection for drains or taps subject to infrequent use. an automatic device that injects a small amount of water into the trap every time there is a pressure drop in the system

trap seal loss

term used when water seal escapes from the P-trap

direct or self siphoning

this type of trap seal loss occurs when unventilated traps which serves as oval bottom fixtures like lavatories or slop sink

indirect or momentum siphoning

result of minus pressure in the pipe created by heavy discharge of water from a fixture installed on a line serving another fixture at a lower floor which can cause trap seal loss

siphonage

result of minus pressure in the drainage system which can cause trap seal loss

back pressure

caused by plus pressure which can cause trap seal loss

evaporation

trap seal loss on floor drains not regularly used to admit water is due to _____

wind effect

trap seal loss cause by wind velocity passing over the top of the soil pipe

capillary action

trap seal loss caused by foreign objects like thread or string suspended

1 FU

maximum trap loading of 32mm pipe size

3 FU

maximum trap loading of 38mm pipe size

4 FU

maximum trap loading of 51mm pipe size

6 FU

maximum trap loading of 76mm pipe size

8 FU

maximum trap loading of 102mm pipe size

interceptors

_____ are needed for fish, fowl and animal slaughter, meat packing or curing establishments, etc

ladders

each interceptor or clarifier shall be readily accessible without _____

1.3 L/s to 3.4 L/s

rate of flow of individual grease trap

flow control

_____ shall be installed in the visible location such as the fixture’s tailpiece or drain outlet connected to grease trap and shall not be adjustable or removable

4

maximum fixtures to be discharged into 1 grease trap

51mm

depth water seal for grease trap

prohibited

water-jacketed grease trap or grease interceptor is ______

12.7mm

laundry equipment that does not have an integral strainer must have an interceptor with a wire basket that will prevent passage of ____ or larger solids such as strings, rags, buttons, etc

76mm

minimum inlet and outlet pipe size of a sand receptor

2 sections

sand interceptor shall have an interior baffle for the separation of _____

2

minimum number of baffle openings

staggered

baffle openings of sand receptors shall have same diameter as the outlet and that the openings shall be _____ to avoid straight line flow

lower

invert of inlet pipe of a sand receptor shall be no ____ than the invert of outlet pipe

0.09 sq.m.

for each 18.9 LPM flow or fraction thereof over 75.7 LPM, the area of the sand interceptor inlet section is to be increased by _____

2 compartments

minimum compartments of interceptors