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Chapter 7 — SANITARY DRAINAGE

702.1 Trap Size. The unit equivalent of plumbing fixtures

California Plumbing Code (Title 24, Part 5) · 2022 edition · updated 2026-09-10 · California

Italicized text is a California amendment to the model code, as printed in the official publication.

shown in Table 702.1 shall be based on the size of the trap

2022 CALIFORNIA PLUMBING CODE 165

SANITARY DRAINAGE

TABLE 701.2 MATERIALS FOR DRAIN, WASTE, VENT PIPE AND FITTINGS

MATERIAL UNDERGROUND
DRAIN, WASTE,
VENT PIPE AND
FITTINGS		 ABOVEGROUND
DRAIN, WASTE,
VENT PIPE AND
FITTINGS		 BUILDING SEWER
PIPE AND FITTINGS		 REFERENCED STAN-
DARD(S) PIPE		 REFERENCED
STANDARD(S)
FITTINGS
ABS (Schedule 40) X X X ASTM D2661,
ASTM D2680*		 ASME A112.4.4,
ASTM D2661,
ASTM D2680*
Cast-Iron X X X ASTM A74,
ASTM A888,
CISPI 301		 ASME B16.12,
ASTM A74,
ASTM A888,
CISPI 301
Co-Extruded ABS (Schedule 40) X X X ASTM F628 ASME A112.4.4,
ASTM D2661,
ASTM D2680*
Co-Extruded Composite
(Schedule 40)		 X X X ASTM F1488 ASME A112.4.4,
ASTM D2661,
ASTM D2665,
ASTM F794*,
ASTM F1866
Co-Extruded PVC (Schedule 40) X X X ASTM F891,
ASTM F1760		 ASME A112.4.4,
ASTM D2665,
ASTM F794*****,
ASTM F1336***,**
ASTM F1866
Copper and Copper Alloys (Type
DWV)		 X X X ASTM B43,
ASTM B75,
ASTM B251,
ASTM B302,
ASTM B306		 ASME B16.23,
ASME B16.29
Galvanized Malleable Iron –– X –– –– ASME B16.3
Galvanized Steel –– X –– ASTM A53 ––
Polyethylene –– –– X ASTM F714,
ASTM F894		 ––
PVC (Schedule 40) X X X ASTM D1785,
ASTM D2665,
ASTM F794*		 ASME A112.4.4,
ASTM D2665,
ASTM F794*,
ASTM F1866
PVC (Sewer and Drain) –– –– X ASTM D2729 ASTM D2729
PVC PSM –– –– X ASTM D3034 ASTM D3034
Stainless Steel 304 –– X –– ASME A112.3.1 ASME A112.3.1
Stainless Steel 316L X X X ASME A112.3.1 ASME A112.3.1
Vitrified Clay (Extra strength) –– –– X ASTM C700 ASTM C700
  • For building sewer applications.

166 2022 CALIFORNIA PLUMBING CODE

SANITARY DRAINAGE

TABLE 702.1 DRAINAGE FIXTURE UNIT VALUES (DFU)

PLUMBING APPLIANCES, APPURTENANCES, OR FIXTURES MINIMUM SIZE TRAP
AND TRAP ARM7
(inches)		 PRIVATE PUBLIC
Bathtub or Combination Bath/Shower 11⁄2 2.0 2.0
Bidet 11⁄4 1.0 ––
Bidet 11⁄2 2.0 ––
Clothes Washer, domestic, standpipe5 2 3.0 3.0
Dental Unit, cuspidor 11⁄4 –– 1.0
Dishwasher, domestic, with independent drain2 11⁄2 2.0 2.0
Drinking Fountain or Water Cooler 11⁄4 0.5 0.5
Food Waste Disposer, commercial 2 –– 3.0
Floor Drain, emergency 2 –– 0.0
Floor Drain (for additional sizes see Section 702.0) 2 2.0 2.0
Shower, single-head trap 29 2.0 2.0
Multi-head, each additional 2 1.0 1.0
Lavatory 11⁄4 1.0 1.0
Lavatories in sets 11⁄2 2.0 2.0
Washfountain 11⁄2 –– 2.0
Washfountain 2 –– 3.0
Mobilehome or Manufactured Home, trap_10_ 3 6.0 ––
Receptor, indirect waste1,3 11⁄2 11⁄2 11⁄2
Receptor, indirect waste1,4 2 2 2
Receptor, indirect waste1 3 3 3
Sinks –– –– ––
Bar 11⁄2 1.0 ––
Bar2 11⁄2 –– 2.0
Clinical 3 –– 6.0
Commercial with food waste2 11⁄2 –– 3.0
Exam Room 11⁄2 –– 1.0
Special Purpose2 11⁄2 2.0 3.0
Special Purpose 2 3.0 4.0
Special Purpose 3 –– 6.0
Kitchen, domestic2
(with or without food waste disposer, dishwasher, or both)		 11⁄2 2.0 2.0
Laundry2 (with or without discharge from a clothes washer) 11⁄2 2.0 2.0
Service or Mop Basin 2 –– 3.0
Service or Mop Basin 3 –– 3.0
Service, flushing rim 3 –– 6.0
Wash, each set of faucets –– –– 2.0
Nonwater Urinal with Drain Cleansing Action 2 1.0 1.0
Urinal, integral trap 1.0 GPF2 2 2.0 2.0
Urinal, integral trap greater than 1.0 GPF 2 2.0 2.0
Urinal, exposed trap2 11⁄2 2.0 2.0
Water Closet, 1.6 GPF Gravity Tank6 3 3.0 4.0

2022 CALIFORNIA PLUMBING CODE 167

SANITARY DRAINAGE

TABLE 702.1 DRAINAGE FIXTURE UNIT VALUES (DFU) (continued)

PLUMBING APPLIANCES, APPURTENANCES, OR FIXTURES MINIMUM SIZE TRAP
AND TRAP ARM7
(inches)		 PRIVATE PUBLIC ASSEMBLY8
Water Closet, 1.6 GPF Flushometer Tank6 3 3.0 4.0 6.0
Water Closet, 1.6 GPF Flushometer Valve6 3 3.0 4.0 6.0
Water Closet, greater than 1.6 GPF Gravity Tank6 3 4.0 6.0 8.0
Water Closet, greater than 1.6 GPF Flushometer Valve6 3 4.0 6.0 8.0

For SI units: 1 inch = 25 mm Notes: 1 Indirect waste receptors shall be sized based on the total drainage capacity of the fixtures that drain thereinto, in accordance with Table 702.2. 2 Provide a 2 inch (50 mm) minimum drain. 3 For refrigerators, coffee urns, water stations, and similar low demands. 4 For commercial sinks, dishwashers, and similar moderate or heavy demands. 5 Buildings having a clothes-washing area with clothes washers in a battery of three or more clothes washers shall be rated at 6 fixture units each for purposes of sizing common horizontal and vertical drainage piping. 6 Water closets shall be computed as 6 fixture units where determining septic tank sizes based on Appendix H of this code. 7 Trap sizes shall not be increased to the point where the fixture discharge is capable of being inadequate to maintain their self-scouring properties. 8 Assembly [Public Use (see Table 422.1)]. 9 For a bathtub to shower retrofit, a 11 / 2 inch (40 mm) trap and trap arm shall be permitted with a maximum shower size of 36 inches (914 mm) in width and 60 inches (1524 mm) in length. See Section 408.5 and Section 408.6. 10 For drainage fixture unit values related to lots within mobilehome parks in all parts of the State of California, see California Code of Regulations, Title 25, Division 1, Chapter 2, Article 5, Section 1268. For drainage fixture unit values related to lots within special occupancy parks in all parts of the State of Cal- ifornia, see California Code of Regulations, Title 25, Division 1, Chapter 2.2, Article 5, Section 2268.

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required, and the unit equivalent of fixtures and devices not shown in Table 702.1 shall be based on the size of trap or trap arm.

Maximum drainage fixture units for a fixture trap and trap arm loadings for sizes up to 4 inches (100 mm) shall be in accordance with Table 702.1(1).

TABLE 702.1(1) MAXIMUM DRAINAGE FIXTURE UNITS FOR A

TRAP AND TRAP ARM*

SIZE OF TRAP AND
TRAP ARM (inches)		 DRAINAGE FIXTURE UNIT
VALUES (DFU)


11⁄4		 1 unit


11⁄2		 3 units


2		 4 units


3		 6 units


4		 8 units

For SI Units: 1 inch = 25 mm

*** Exception:** On self-service laundries.

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▸Contents — California Plumbing Code (Title 24, Part 5)
California Plumbing Code (Title 24, Part 5)
  1. Chapter 1 — GENERAL CODE PROVISIONS
  2. Chapter 2 — DEFINITIONS
  3. Chapter 3 — GENERAL REGULATIONS
  4. Chapter 4 — PLUMBING FIXTURES AND FIXTURE FITTINGS
  5. Chapter 5 — WATER HEATERS
  6. Chapter 6 — WATER SUPPLY AND DISTRIBUTION
  7. ▸Chapter 7 — SANITARY DRAINAGE
    Overview
    1. 701.1 Applicability. This chapter shall govern the materials,
    2. 701.2 Drainage Piping. Materials for drainage piping shall
    3. 701.3 Drainage Fittings. Materials for drainage fittings
    4. 701.4 Continuous Wastes. Continuous wastes and fixture
    5. 701.5 Lead. (See Chapter 17) Sheet lead shall comply with
    6. 701.6 Caulking Ferrules. Caulking ferrules shall be manufactur…
    7. 701.7 Soldering Bushings. Soldering bushings shall be
    8. 702.1 Trap Size. The unit equivalent of plumbing fixtures
    9. 702.2 Intermittent Flow. Drainage fixture units for intermitte…
    10. 702.3 Continuous Flow. For a continuous flow into a
    11. 703.1 Minimum Size. The minimum sizes of vertical, horizontal,…
    12. 703.2 Maximum Number of Fixture Units. Table 703.2
    13. 703.3 Sizing per Appendix C. For alternate method of
    14. 704.1 Inlet Fittings. Drainage piping shall be provided with
    15. 704.2 Single Vertical Drainage Pipe. Two fixtures set
    16. 704.3 Commercial Sinks. Pot sinks, scullery sinks, dishwashing…
    17. 705.1 ABS and ABS Co-Extruded Plastic Pipe and
    18. 705.2 Cast-Iron Pipe and Joints. Joining methods for
    19. 705.3 Copper or Copper Alloy Pipe (DWV) and
    20. 705.4 Galvanized Steel Pipe and Joints. Joining methods for ga…
    21. 705.5 Polyethylene (PE) Sewer Pipe. Polyethylene (PE)
    22. 705.6 PVC and PVC Co-Extruded Plastic Pipe and
    23. 705.7 Stainless Steel Pipe and Joints. Joining methods for sta…
    24. 705.8 Vitrified Clay Pipe and Joints. Joining methods
    25. 705.9 Special Joints. Special joints shall comply with Section…
    26. 705.10 Joints Between Various Materials. Joints
    27. 706.1 Approved Fittings. Changes in the direction of
    28. 706.2 Horizontal to Vertical. Horizontal drainage lines,
    29. 706.3 Horizontal to Horizontal. Horizontal drainage lines
    30. 706.4 Vertical to Horizontal. Vertical drainage lines connecti…
    31. 707.1 Plug. Each cleanout fitting for cast-iron pipe shall con…
    32. 707.2 Approved. Each cleanout fitting and each cleanout
    33. 707.3 Watertight and Gastight. Cleanouts shall be
    34. 707.4 Location. Each horizontal drainage pipe shall be provide…
    35. 707.5 Cleaning. Each cleanout shall be installed so that it
    36. 707.6 Extension. Each cleanout extension shall be considered a…
    37. 707.7 Interceptor. Each cleanout for an interceptor shall be
    38. 707.8 Access. Each cleanout, unless installed under an
    39. 707.9 Clearance. Each cleanout in piping 2 inches (50 mm)
    40. 707.10 Fittings. Cleanout fittings shall be not less in size
    41. 707.11 Pressure Drainage Systems. Cleanouts shall be
    42. 707.12 Countersunk Cleanout Plugs. Countersunk
    43. 707.13 Hubless Blind Plugs. Where a hubless blind plug
    44. 707.14 Trap Arms. Cleanouts for trap arms shall be installed
    45. 708.1 General. Horizontal drainage piping shall be run in
    46. 709.1 General. Where practicable, plumbing fixtures shall
    47. 710.1 Backflow Protection. Fixtures installed on a floor
    48. 710.2 Sewage Discharge. Drainage piping serving fixtures that …
    49. 710.3 Sewage Ejector and Pumps. A sewage ejector or
    50. 710.4 Discharge Line. The discharge line from such ejector, pu…
    51. 710.5 Size of Building Drains and Sewers. Building
    52. 710.6 Backwater Valves. Backwater valves, gate valves,
    53. 710.7 Drainage and Venting Systems. The drainage and
    54. 710.8 Sump and Receiving Tank Construction. Sumps
    55. 710.9 Alarm. Such sumps and receiving tanks shall be automatic…
    56. 710.10 Sump and Receiving Tank Covers and Vents.
    57. 710.11 Air Tanks. Air tanks shall be so proportioned as to be
    58. 710.12 Grinder Pump Ejector. Grinder pumps shall be
    59. 710.13 Macerating Toilet Systems and Pumped
    60. 711.1 General. Drainage connections shall not be made into
    61. 712.1 Media. The piping of the plumbing, drainage, and
    62. 712.2 Water Test. The water test shall be applied to the
    63. 712.3 Air Test. The air test shall be made by attaching an
    64. 713.1 Where Required. A building in which plumbing fixtures ar…
    65. 713.2 Private Sewage Disposal System. Where no public sewer in…
    66. 713.3 Public Sewer. Within the limits prescribed by Section 71…
    67. 713.4 Public Sewer Availability. The public sewer shall
    68. 713.5 Permit. No permit shall be issued for the installation,
    69. 713.6 Lot. On every lot or premises hereafter connected to
    70. 713.7 Installation. In cities, counties, or both where the
    71. 714.1 Unlawful Practices. It shall be unlawful for a person to…
    72. 714.2 Prohibited Water Discharge. No rain, surface, or
    73. 714.3 Prohibited Sewer Connection. No cesspool, septic tank, s…
    74. 714.4 Commercial Food Waste Disposer. The Authority Having Jur…
    75. 714.5 Tanks. An approved type, watertight sewage or wastewater…
    76. 715.1 Materials. The building sewer, beginning 2 feet (610
    77. 715.2 Joining Methods and Materials. Joining methods
    78. 715.3 Existing Sewers. Replacement of existing building
    79. 716.1 General. Pipe, brick, block, prefabricated septic tanks,
    80. 717.1 General. The minimum size of a building sewer shall
    81. 717.2 [AGR] Meat and Poultry Processing Plants. The
    82. 718.1 Slope. Building sewers shall be run in practical alignme…
    83. 718.2 Support. Building sewer piping shall be laid on a firm
    84. 718.3 Protection from Damage. No building sewer or
    85. 719.1 Locations. Cleanouts shall be placed inside the building…
    86. 719.2 No Additional Cleanouts. Where a building sewer
    87. 719.3 Building Sewer Cleanouts. Required building
    88. 719.4 Cleaning. Each cleanout shall be installed so that it
    89. 719.5 Access. Cleanouts installed under concrete or asphalt
    90. 719.6 Manholes. Approved manholes shall be permitted to
    91. 720.1 General. Building sewers or drainage piping of clay
    92. 721.1 Building Sewer. Except as provided in Section 721.2,
    93. 721.2 Abutting Lot. Nothing contained in this code shall be
    94. 722.1 Building (House) Sewer. An abandoned building
    95. 722.2 Cesspools, Septic Tanks, and Seepage Pits. A
    96. 722.3 Filling. The top cover or arch over the cesspool, septic…
    97. 722.4 Ownership. No person owning or controlling a
    98. 722.5 Disposal Facilities. Where disposal facilities are
    99. 723.1 General. Building sewers shall be tested by plugging
    100. 724.1 The drainage and plumbing systems must permit the
    101. 724.2 Toilet soil lines shall be separated from house drainage
    102. 726.1 The outer premises of every official establishment,
    103. 726.2 Toilet soil lines shall be separated from house drainage
    104. 727.1 For new acute care hospital buildings submitted after
  8. Chapter 8 — INDIRECT WASTES
  9. Chapter 9 — VENTS
  10. Chapter 10 — TRAPS AND INTERCEPTORS
  11. Chapter 11 — STORM DRAINAGE
  12. Chapter 12 — FUEL GAS PIPING
  13. Chapter 13 — HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICA…
  14. Chapter 14 — FIRESTOP PROTECTION
  15. Chapter 15 — ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS
  16. Chapter 16 — NONPOTABLE RAINWATER CATCHMENT SYSTEMS
  17. Chapter 17 — REFERENCED STANDARDS
  18. Appendix A — RECOMMENDED RULES FOR SIZING THE WATER SUPPLY SYS…
  19. Appendix B — EXPLANATORY NOTES ON COMBINATION WASTE AND VENT S…
  20. Appendix C — ALTERNATE PLUMBING SYSTEMS
  21. Appendix D — SIZING STORM WATER DRAINAGE SYSTEMS
  22. Appendix E — MANUFACTURED/MOBILE HOME PARKS AND RECREATIONAL V…
  23. Appendix F — FIREFIGHTER BREATHING AIR REPLENISHMENT SYSTEMS
  24. Appendix G — SIZING OF VENTING SYSTEMS
  25. Appendix H — PRIVATE SEWAGE DISPOSAL SYSTEMS
  26. Appendix I — INSTALLATION STANDARDS
  27. Appendix J — COMBINATION OF INDOOR AND OUTDOOR COMBUSTION AND …
  28. Appendix K — POTABLE RAINWATER CATCHMENT SYSTEMS
  29. Appendix L — SUSTAINABLE PRACTICES
  30. Appendix M — PEAK WATER DEMAND CALCULATOR
  31. Appendix N — IMPACT OF WATER TEMPERATURE ON THE POTENTIAL FOR …

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