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Chapter 7 — SANITARY DRAINAGE

704.2 Single Vertical Drainage Pipe. Two fixtures set

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.

back-to-back, or side-by-side, within the distance allowed between a trap and its vent, shall be permitted to be served by a single vertical drainage pipe provided that each fixture wastes separately into an approved double-fixture fitting having inlet openings at the same level.

168 2022 CALIFORNIA PLUMBING CODE

SANITARY DRAINAGE

TABLE 703.2 MAXIMUM UNIT LOADING AND MAXIMUM LENGTH OF DRAINAGE AND VENT PIPING

SIZE OF PIPE (inches) 11⁄4 11⁄2 2 3 4 5 6 8 10 12
Maximum Units
Drainage Piping1
Vertical
Horizontal

1
1

22, 7
17

163
83

484
354

256
2165

600
4285

1380
7205

3600
26405

5600
46805

8400
82005
Maximum Length
Drainage Piping
Vertical, (feet)
Horizontal (unlimited)

45

65

85

212

300

390

510

750

–

–
Vent Piping
Horizontal and Vertical6
Maximum Units
Maximum Lengths, (feet)

1
45

83
60

24
120

84
212

256
300

600
390

1380
510

3600
750

–

–

For SI units: 1 inch = 25 mm, 1 foot = 304.8 mm Notes: 1 Excluding trap arm. 2 Except for sinks, urinals, and dishwashers – exceeding 1 fixture unit. 3 Except for six-unit traps or water closets. 4 Not to exceed five water closets or five six-unit traps. 5 Based on 1 ⁄ 4 inch per foot (20.8 mm/m) slope. For 1 ⁄ 8 of an inch per foot (10.4 mm/m) slope, multiply horizontal fixture units by a factor of 0.8. 6 The diameter of an individual vent shall be not less than 11 ⁄ 4 inches (32 mm) nor less than one-half the diameter of the drain to which it is connected. Fixture unit load values for drainage and vent piping shall be computed from Table 702.1 and Table 702.2. Not to exceed one-third of the total permitted length of a vent shall be permitted to be installed in a horizontal position. Where vents are increased one pipe size for their entire length, the maximum length limitations specified in this table do not apply. This table is in accordance with the requirements of Section 901.3. 7 Up to 8 public lavatories are permitted to be installed on a 11 ⁄ 2 inch (40 mm) vertical branch or horizontal sanitary branch sloped at 1 ⁄ 4 inch per foot (20.8 mm/m).

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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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