Trap requirements, trap primers, and maximum trap/trap-arm loads

Grounded in the retrieved California Plumbing Code — click a citation to read the verbatim passage:

• CPC § 1.6 High relevance — show source text

  PLUMBING APPLIANCES, APPURTENANCES, OR FIXTURES	MINIMUM SIZE TRAP AND TRAP ARM7 (inches)	PRIVATE	PUBLIC	ASSEMBLY8
  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 1 1 / 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 408.6 and Section 408.7. 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.

  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.

  702.2 Intermittent Flow. Drainage fixture units for intermittent flow into the drainage system shall be computed on the rated discharge capacity in gallons per minute (gpm) (L/s) in accordance with Table 702.2.

  TABLE 702.1(1) MAXIMUM DRAINAGE FIXTURE UNITS FOR A

  TRAP AND TRAP ARM*

• CPC § 1001.0 Medium relevance — show source text

  ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

  CHAPTER 10

  TRAPS AND INTERCEPTORS

  1001.0 General.

  1001.1 Applicability. This chapter shall govern the materials, design, and installation of traps and interceptors.

  1001.2 Where Required. Each plumbing fixture shall be separately trapped by an approved type of liquid seal trap. This section shall not apply to fixtures with integral traps. Not more than one trap shall be permitted on a trap arm. Food waste disposers installed with a set of restaurant, commercial, or industrial sinks shall be connected to a separate trap.

  Each domestic clothes washer and each laundry sink shall be connected to a separate and independent trap, except that a trap serving a laundry sink shall also be permitted to receive the waste from a clothes washer set adjacent to it.

  The vertical distance between a fixture outlet and the trap weir shall be as short as practicable, but in no case shall the tailpiece exceed 24 inches (610 mm) in length.

  One trap shall be permitted to serve a set of not more than three single compartment sinks or laundry sinks of the same depth or three lavatories immediately adjacent to each other and in the same room where the waste outlets are not more than 30 inches (762 mm) apart, and the trap is centrally located where three compartments are installed.

  1002.0 Traps Protected by Vent Pipes.

  1002.1 Vent Pipes. Each plumbing fixture trap, except as otherwise provided in this code, shall be protected against siphonage, backpressure, and air circulation shall be assured throughout the drainage system using a vent pipe installed in accordance with the requirements of this code.

  1002.2 Fixture Traps. Each fixture trap shall have a protecting vent so located that the developed length of the trap arm from the trap weir to the inner edge of the vent shall be within the distance given in Table 1002.2 but in no case less than two times the diameter of the trap arm. 1002.3 Change of Direction. A trap arm shall be permitted to change direction without the use of a cleanout where such change of direction does not exceed 90 degrees (1.57 rad). Horizontal changes in the direction of trap arms shall be in accordance with Section 706.3.

  Exception: For trap arms, 3 inches (80 mm) in diameter and larger, the change of direction shall not exceed 135 degrees (2.36 rad) without the use of a cleanout. 1002.4 Vent Pipe Opening. The vent pipe opening from soil or waste pipe, except for water closets and similar fixtures, shall not be below the weir of the trap.

  1003.0 Traps – Described. 1003.1 General Requirements. Each trap, except for traps within an interceptor or similar device shall be selfcleaning. Traps for bathtubs, showers, lavatories, sinks, laun

  dry sinks, floor drains, urinals, drinking fountains, dental units, and similar fixtures shall be of standard design, weight and shall be of ABS, cast-brass, cast-iron, lead, PP, PVC, or other approved material. An exposed and readily accessible drawn-copper alloy tubing trap, not less than 17 B & S Gauge (0.045 inch) (1.143 mm), shall be permitted to be used on fixtures discharging domestic sewage.

  Exception s :

• CPC § 25.4 Medium relevance — show source text

  For SI units: 1 inch = 25.4 mm

  Notes: 1 Maintain 1 ⁄ 4 inch per foot slope (20.8 mm/m). 2 The developed length between the trap of a water closet or similar fixture (measured from the face of the closet flange to the inner edge of the vent) and its vent shall not exceed 6 feet (1829 mm). 3 Horizontally wet vented bathtubs, showers and similar fixtures shall be limited to a maximum of 6 feet (1829 mm) for 1½ inch (40 mm) fixture drains and 8 feet (2438 mm) for 2 inch (50 mm) fixture drains, maintaining ¼ inch per foot slope (20.8 mm/m).

  1003.2 Slip Joint Fittings. A maximum of one approved slip joint fitting shall be permitted to be used on the outlet side of a trap, and no tubing trap shall be installed without a listed tubing trap adapter. Listed plastic trap adapters shall be permitted to be used to connect listed metal tubing traps.

  1003.3 Size. The size (nominal diameter) of a trap for a given fixture shall be sufficient to drain the fixture rapidly but in no case less than nor more than one pipe size larger than given in Table 702.1. The trap shall be the same size as the trap arm to which it is connected.

  TABLE 1002.2

  HORIZONTAL LENGTHS OF TRAP ARMS (EXCEPT FOR WATER CLOSETS AND SIMILAR FIXTURES) [1, 2, 3]

  For SI units: 1 inch = 25.4 mm

  Notes: 1 Maintain 1 ⁄ 4 inch per foot slope (20.8 mm/m). 2 The developed length between the trap of a water closet or similar fixture (measured from the face of the closet flange to the inner edge of the vent) and its vent shall not exceed 6 feet (1829 mm). 3 Horizontally wet vented bathtubs, showers and similar fixtures shall be limited to a maximum of 6 feet (1829 mm) for 1½ inch (40 mm) fixture drains and 8 feet (2438 mm) for 2 inch (50 mm) fixture drains, maintaining ¼ inch per foot slope (20.8 mm/m).

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  TRAPS AND INTERCEPTORS

  1004.0 Traps.

  1004.1 Prohibited. No form of trap that depends for its seal upon the action of movable parts shall be used. No trap that has concealed interior partitions, except those of plastic, glass, or similar corrosion-resisting material, shall be used. “S” traps, bell traps, and crown-vented traps shall be prohibited. No fixture shall be double trapped. Drum and bottle traps shall be installed for special conditions. No trap shall be installed without a vent, except as otherwise provided in this code.

  1004.2 Movable Parts. Bladders, check valves or another type of devices with moveable parts shall be prohibited to serve as a trap.

• CPC § 307.1 Medium relevance — show source text

  b_**|NUMBER OF LAB SUITES PER FLOOR BASED ON CONSTRUCTION TYPE|NUMBER OF LAB SUITES PER FLOOR BASED ON CONSTRUCTION TYPE|NUMBER OF LAB SUITES PER FLOOR BASED ON CONSTRUCTION TYPE|NUMBER OF LAB SUITES PER FLOOR BASED ON CONSTRUCTION TYPE|NUMBER OF LAB SUITES PER FLOOR BASED ON CONSTRUCTION TYPE| |STORY|STORY|PERCENTAGE OF MAXIMUM
  ALLOWABLE QUANTITY PER
  LABORATORY SUITEa, b|Type IA|Type IB|Type IIA,
  IIIA, IV|Type IIB, IIIB,
  VA|Type VB| |Above grade
  plane|Above 20|0|NP|NP|NP|NP|NP| |Above grade
  plane|15 to 20|25|4|NP|NP|NP|NP| |Above grade
  plane|11, 12, 13, 14|50|8|NP|NP|NP|NP| |Above grade
  plane|7, 8, 9, 10|50|16|NP|NP|NP|NP| |Above grade
  plane|6|75|20|20|NP|NP|NP| |Above grade
  plane|4, 5|75|20|20|20|NP|NP| |Above grade
  plane|3|100|UL|UL|UL|UL|NP| |Above grade
  plane|1, 2|100|UL|UL|UL|UL|UL| |Below grade
  plane|1|75c|10|10|10|10|10| |Below grade
  plane|2|50d|5|5|5|5|5| |Below grade
  plane|3 and below|0|NP|NP|NP|NP|NP| |UL = Unlimited, NP = Not permitted
  a. Percentages shall be of the maximum allowable quantity per laboratory suite shown in Tables 307.1(1) and 307.1(2). Allowable hazardous material increases for buildings
  equipped throughout with an automatic sprinkler system shall not be applicable to Group L occupancies.
  b. When an individual laboratory suite occupies more than one story, the more restrictive percentage of the maximum allowable quantity per laboratory suite shall apply.
  c. The total aggregate quantity of flammable liquids on the first story below grade shall be limited to the maximum total aggregate quantity for Group B occupancy control areas.
  d. The total aggregate quantity of flammable liquids on the second story level below grade shall be limited to a maximum total aggregate quantity for Group B occupancy control
  areas.|UL = Unlimited, NP = Not permitted
  _a.

• CPC § 2.2 Medium relevance — show source text

  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.

  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.

  702.2 Intermittent Flow. Drainage fixture units for intermittent flow into the drainage system shall be computed on the rated discharge capacity in gallons per minute (gpm) (L/s) in accordance with Table 702.2.

  TABLE 702.1(1) MAXIMUM DRAINAGE FIXTURE UNITS FOR A

  TRAP AND TRAP ARM*

  For SI Units: 1 inch = 25 mm

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

  TABLE 702.2

  DISCHARGE CAPACITY IN GALLONS PER MINUTE FOR

  INTERMITTENT FLOW ONLY*

  GPM	FIXTURE UNITS
  Up to 71⁄2	Equals 1 Fixture Unit
  Greater than 71⁄2 to 15	Equals 2 Fixture Units
  Greater than 15 to 30	Equals 4 Fixture Units
  Greater than 30 to 50	Equals 6 Fixture Units

  For SI units: 1 gallon per minute = 0.06 L/s

  • Discharge capacity exceeding 50 gallons per minute (3.15 L/s) shall be determined by the Authority Having Jurisdiction.

  702.3 Continuous Flow. For a continuous flow into a drainage system, such as from a pump, sump ejector, air conditioning equipment, or similar device, 2 fixture units shall be equal to each gallon per minute (gpm) (L/s) of flow.

  703.0 Size of Drainage Piping. 703.1 Minimum Size. The minimum sizes of vertical, horizontal, or both drainage piping shall be determined from the total of fixture units connected thereto, and additionally, in the case of vertical drainage pipes, in accordance with their length.

  703.2 Maximum Number of Fixture Units. Table 703.2

  shows the maximum number of fixture units allowed on a vertical or horizontal drainage pipe, building drain, or building sewer of a given size; the maximum number of fixture units allowed on a branch interval of a given size; and the maximum length (in feet and meters) of a vertical drainage pipe of a given size. 703.3 Sizing per Appendix C. For alternate method of sizing drainage piping, see Appendix C.

• CPC § 5.106.8 Medium relevance — show source text

  notes and
  table)|5.106.8 through
  5.106.8.2||||| |(continued)
  DIVISION 5.1
  Planning and
  Design
  Select One Elective|(continued)
  DIVISION 5.1
  Planning and
  Design
  Select One Elective|Mandatory|Grading and paving (exception for additions and
  alterations not altering the drainage path)|5.106.10||||| |(continued)
  DIVISION 5.1
  Planning and
  Design
  Select One Elective|(continued)
  DIVISION 5.1
  Planning and
  Design
  Select One Elective|Tier 1
  Prerequisite|Cool roof (A5.106.11.2.2): SRI 75 when≤_ 2:12, SRI 16 when >_
  2:12|A5.106.11.2||||| |(continued)
  DIVISION 5.1
  Planning and
  Design
  Select One Elective|Select One Elective|Elective|Community connectivity|A5.103.1||||| |(continued)
  DIVISION 5.1
  Planning and
  Design
  Select One Elective|Select One Elective|Elective|Brownfield or greyfield site redevelopment or infill area
  development|A5.103.2
  A5.103.2.1||||| |(continued)
  DIVISION 5.1
  Planning and
  Design
  Select One Elective|Select One Elective|Elective|Reduce development footprint and optimize open space|A5.104.1, A5.104.1.1,
  A5.104.1.2, A5.104.1.3||||| |(continued)
  DIVISION 5.1
  Planning and
  Design
  Select One Elective|Select One Elective|Elective|Deconstruction and reuse of existing structures, Scope with
  Exceptions, Reuse of existing building, Tier 1 and Verification
  of compliance with Note|A5.105.1, A5.105.2
  and A5.105.2.1 and
  A5.105.2.3||||| |(continued)
  DIVISION 5.1
  Planning and
  Design
  Select One Elective|Select One Elective|Elective|Storm water design|A5.106.2, A5.106.2.1,
  A5.106.2.2||||| |(continued)
  DIVISION 5.1
  Planning and
  Design
  Select One Elective|Select One Elective|Elective|Low Impact Development (LID)|A5.106.3, A5.106.3.1,
  _A5.106.3.

• CPC § 1.11.0. Medium relevance — show source text

  1 Exception 2_||||X|X|||||||||||||||||||| |1010.2|||||||||||||||||||X|||||| |1010.3|||||||||||||||||||X|||||| |1010.4|||||||||||||||||||X|||||| |1010.5|||||||||||||||||||X|||||| |1014.1A, B, C||||||||||X|X|X|X|X|X|||||||||| |1015.5||||||||||X|X|X|X|X|X|||||||||| |1015.6||||||||||X|X|X|X|X|X||||||||||

  This state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.0.

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  CHAPTER 10

  TRAPS AND INTERCEPTORS

  1001.0 General.

  1001.1 Applicability. This chapter shall govern the materials, design, and installation of traps and interceptors.

  1001.2 Where Required. Each plumbing fixture shall be separately trapped by an approved type of liquid seal trap. This section shall not apply to fixtures with integral traps. Not more than one trap shall be permitted on a trap arm. Food waste disposers installed with a set of restaurant, commercial, or industrial sinks shall be connected to a separate trap.

  Each domestic clothes washer and each laundry sink shall be connected to a separate and independent trap, except that a trap serving a laundry sink shall also be permitted to receive the waste from a clothes washer set adjacent to it.

  The vertical distance between a fixture outlet and the trap weir shall be as short as practicable, but in no case shall the tailpiece exceed 24 inches (610 mm) in length.

  One trap shall be permitted to serve a set of not more than three single compartment sinks or laundry sinks of the same depth or three lavatories immediately adjacent to each other and in the same room where the waste outlets are not more than 30 inches (762 mm) apart, and the trap is centrally located where three compartments are installed.

  1002.0 Traps Protected by Vent Pipes.

  1002.1 Vent Pipes. Each plumbing fixture trap, except as otherwise provided in this code, shall be protected against siphonage, backpressure, and air circulation shall be assured throughout the drainage system using a vent pipe installed in accordance with the requirements of this code.

• CPC § 25.4 Medium relevance — show source text

  SP 30**|** GM, GC, SM,
  SM-SC and ML 45| SC, ML-CL and**
  inorganic CL 60| |8|4|4 @ 48|4 @ 46|6 @ 39| |8|5|4 @ 45|5 @ 46|6 @ 47| |8|6|5 @ 45|6 @ 40|DR| |8|7|6 @ 44|DR|DR| |8|8|6 @ 32|DR|DR| |9|4|4 @ 48|4 @ 46|4 @ 37| |9|5|4 @ 42|5 @ 43|6 @ 44| |9|6|5 @ 41|6 @ 37|DR| |9|7|6 @ 39|DR|DR| |9|> 8|DRi|DR|DR| |10|4|4 @ 48|4 @ 46|4 @ 35| |10|5|4 @ 40|5 @ 40|6 @ 41| |10|6|5 @ 38|6 @ 34|DR| |10|7|6 @ 36|DR|DR| |10|> 8|DR|DR|DR| |For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot per foot = 0.1571 kPa2/m, 1 pound per square inch = 6.895 kPa.
  DR = Design Required.
  a. Soil classes are in accordance with the Unified Soil Classification System. Refer to Table R401.4.1(2).
  b. Table values are based on reinforcing bars with a minimum yield strength of 60,000 psi concrete with a minimum specified compressive strength of 2,500 psi and vertical rein-
  forcement being located at the centerline of the wall. See Section R404.1.3.3.7.2.
  c. Maximum spacings shown are the values calculated for the specified bar size. Where the bar used is Grade 60 and the size specified in the table, the actual spacing in the wall
  shall not exceed a whole-number multiple of 12 inches (12, 24, 36 and 48) that is less than or equal to the tabulated spacing. Vertical reinforcement with a yield strength of less
  than 60,000 psi and bars of a different size than specified in the table are permitted in accordance with Section R404.1.3.3.7.6 and Table R404.1.3.2(9).
  d. Deflection criterion is_L_/240, where_L_ is the height of the basement wall in inches.
  e. Interpolation is not permitted.
  f. Where walls will retain 4 feet or more of unbalanced backfill, they shall be laterally supported at the top and bottom before backfilling.
  g. See Section R404.1.3.2 for minimum reinforcement required for basement walls supporting above-grade concrete walls.
  h. See Table R608.3 for thicknesses and dimensions of waffle-grid walls.
  i. DR means design is required in accordance with the applicable building code, or in the absence of a code, in accordance with ACI 318.
  j.

• CPC § 222.0 Medium relevance — show source text

  222.0 – T –

  T Rating. The time period that the penetration firestop system, including the penetrating item, limits the maximum temperature rise of 325°F (181°C) above its initial temperature through the penetration on the nonfire side, where tested in accordance with ASTM E814 or UL 1479.

  Tailpiece. The pipe or tubing that connects the outlet of a plumbing fixture to a trap. Testing Agency. [HCD 1] See “Approved Testing Agency”. Thermostatic (Temperature Control) Valve. A mixing valve that senses outlet temperature and compensates for fluctuations in incoming hot or cold water temperatures. Toilet. [OSHPD 1, 2, 3, 4 & 5] A fixture within a toilet room which is used for defecation or urination. Toilet Facility. A room or space containing not less than one lavatory and one water closet.

  Toilet Room. [OSHPD 1, 2, 3, 4 & 5] A room within or on the premises containing water closets, urinals, and other required facilities. Transition Gas Riser. A listed or approved section or sections of pipe and fittings used to convey fuel gas and installed in a gas piping system to provide a transition from belowground to aboveground.

  Trap. A fitting or device so designed and constructed as to provide, where properly vented, a liquid seal that will prevent the back passage of air without materially affecting the flow of sewage or wastewater through it.

  Trap Arm. Those portions of a fixture drain between a trap and the vent.

  Trap Primer. A device and system of piping that maintains a water seal in a remote trap. Trap Seal. The vertical distance between the crown weir and the top dip of the trap. Crown Weir (Trap Weir). The lowest point in the cross-section of the horizontal waterway at the exit of the trap. Top Dip (of the trap). The highest point in the internal cross-section of the trap at the lowest part of the bend (inverted siphon). By contrast, the bottom dip is the lowest point in the internal cross-section. Treated Gray Water. [BSC-CG & HCD 1] Nonpotable water meeting the definition of “gray water” collected and treated on-site suitable for direct beneficial use.

  223.0 – U –

  UPC. [HCD 1] “UPC” is the latest edition of the Uniform Plumbing Code, published by the International Association of Plumbing and Mechanical Officials. Unsanitary. See Insanitary.

  User Outlet. See Station Outlet.

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  DEFINITIONS

  224.0 – V –

  Vacuum. A pressure less than that exerted by the atmosphere.

  Vacuum Breaker. See Backflow Preventer.

• CPC § 25.4 Medium relevance — show source text

  
  (MIN)**| |ITEM CODE|THICKNESS|CONSTRUCTION DETAILS|LOAD|PRE-BMS-92|BMS-92|POST-BMS-92|POST-BMS-92|POST-BMS-92| |FR-I-12|1/2″|1/2″ thick 1:2; 1:3 gypsum plaster on wood
  lath.|15 minutes||1||1–3|15| |FR-I-13|7/8″|1/2″ thick 1:2; 1:2 gypsum plaster on3/8″
  perforated gypsum lath.|30 minutes||1||1–3|30| |FR-I-14|7/8″|1/2″ thick 1:2; 1:2 gypsum plaster on3/8″
  thick plain or indented gypsum plaster.|20 minutes||1||1–3|20| |FR-I-15|3/8″|3/8″ gypsum wallboard.|10 minutes||1||1, 2|10| |FR-I-16|1/2″|1/2″ gypsum wallboard.|15 minutes||1||1, 2|15|

  For SI: 1 inch = 25.4 mm, °C = [(°F) - 32]/1.8.

  Notes:

  1. The finish rating is the time required to obtain an average temperature rise of 250°F, or a single point rise of 325°F, at the interface between the material being rated and the substrate being protected.
  2. Tested in accordance with the Standard Specifications for Fire Tests of Building Construction and Materials, ASA No. A2-1932.
  3. Mix proportions for plasters as follows: first ratio, dry weight of plaster to dry weight of sand for scratch coat; second ratio, plaster to sand for brown coat.
  4. Neat plaster means unsanded wood-fiber gypsum plaster.

  TABLE 1.5.2 FINISH RATINGS—ORGANIC MATERIALS	Col2	Col3	Col4	Col5	Col6	Col7	Col8	Col9
  ITEM CODE	THICKNESS	CONSTRUCTION DETAILS	PERFORMANCE	REFERENCE NUMBER	REFERENCE NUMBER	REFERENCE NUMBER	NOTES	REC. F.R. (min)
  ITEM CODE	THICKNESS	CONSTRUCTION DETAILS	FINISH RATING	PRE-BMS-92	BMS-92	POST-BMS-92	POST-BMS-92	POST-BMS-92
  FR-O-1	9/16″	7/16″ wood fiberboard faced with1/8″ cement-asbestos board.	15 minutes		1		1, 2	15
  FR-O-2	29/32″	3/4″ wood sheathing, asbestos felt weighing 14 lbs/100 ft2 and5/32″ cement-asbestos shingles.	20 minutes		1		1, 2	20
  FR-O-3	11/2″	1″ thick magnesium oxysulfate wood fiber- board faced with 1:3; 1:3 gypsum plaster,1/2″ thick.

• CPC § 19.19 Medium relevance — show source text

  Exception s :

  (1) Drawn-copper alloy tubing traps shall not be used for urinals. Each trap shall have the manufacturer’s name stamped legibly in the metal of the trap, and each tubing trap shall have the gauge of the tubing in addition to the manufacturer’s name. A trap shall have a smooth and uniform interior waterway.

  (2) [HCD 1 & HCD 2] Non-water supplied urinals conform- ing to ASME A112.19.19-2016, Standard for Vitreous China Nonwater Urinals, or reference standards in Table 1701.1 for non-vitreous ceramic or plastic urinal fixtures.

  TABLE 1002.2

  HORIZONTAL LENGTHS OF TRAP ARMS (EXCEPT FOR WATER CLOSETS AND SIMILAR FIXTURES) [1, 2, 3]

  TRAP ARM PIPE DIAMETER (inches)	DISTANCE TRAP TO VENT MINIMUM (inches)	LENGTH MAXIMUM (inches)
  11⁄4	21⁄2	30
  11⁄2	3	42
  2	4	60
  3	6	72
  4	8	120
  Exceeding 4	2 x Diameter	120

  For SI units: 1 inch = 25.4 mm

  Notes: 1 Maintain 1 ⁄ 4 inch per foot slope (20.8 mm/m). 2 The developed length between the trap of a water closet or similar fixture (measured from the face of the closet flange to the inner edge of the vent) and its vent shall not exceed 6 feet (1829 mm). 3 Horizontally wet vented bathtubs, showers and similar fixtures shall be limited to a maximum of 6 feet (1829 mm) for 1½ inch (40 mm) fixture drains and 8 feet (2438 mm) for 2 inch (50 mm) fixture drains, maintaining ¼ inch per foot slope (20.8 mm/m).

  1003.2 Slip Joint Fittings. A maximum of one approved slip joint fitting shall be permitted to be used on the outlet side of a trap, and no tubing trap shall be installed without a listed tubing trap adapter. Listed plastic trap adapters shall be permitted to be used to connect listed metal tubing traps.

  1003.3 Size. The size (nominal diameter) of a trap for a given fixture shall be sufficient to drain the fixture rapidly but in no case less than nor more than one pipe size larger than given in Table 702.1. The trap shall be the same size as the trap arm to which it is connected.

  TABLE 1002.2

  HORIZONTAL LENGTHS OF TRAP ARMS (EXCEPT FOR WATER CLOSETS AND SIMILAR FIXTURES) [1, 2, 3]

  For SI units: 1 inch = 25.4 mm

• CPC § 907.2 Medium relevance — show source text

  907.2 Yoke Vent. The yoke vent connection to the vent stack shall be placed not less than 42 inches (1067 mm) above the floor level, and the yoke vent connection to the drainage stack shall be using a wye-branch fitting placed below the lowest drainage branch connection serving that floor.

  908.0 Wet Venting. 908.1 Vertical Wet Venting. Wet venting is limited to vertical drainage piping receiving the discharge from the trap arm of one and two fixture unit fixtures that also serves as a vent not exceeding four fixtures. Wet-vented fixtures shall be within the same story; provided, further, that fixtures with a continuous vent discharging into a wet vent shall be within the same story as the wet-vented fixtures. No wet vent shall exceed 6 feet (1829 mm) in developed length. 908.1.1 Size. The vertical piping between two consecutive inlet levels shall be considered a wet-vented sec tion. Each wet-vented section shall be not less than one pipe size exceeding the required minimum waste pipe size of the upper fixture or shall be one pipe size exceeding the required minimum pipe size for the sum of the fixture units served by such wet-vented section, whichever is larger, but in no case less than 2 inches (50 mm) in diameter. 908.1.2 Vent Connection. Common vent sizing shall be the sum of the fixture units served but, in no case,

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  VENTS

  smaller than the minimum vent pipe size required for a fixture served, or by Section 904.0. 908.2 Horizontal Wet Venting for a Bathroom Group. A bathroom group located on the same floor level shall be permitted to be vented by a horizontal wet vent where all of the conditions of Section 908.2.1 through Section 908.2.5 are met.

  908.2.1 Vent Connection. The dry vent connection to the wet vent shall be an individual vent for the bidet, shower, or bathtub. One or two vented lavatory(s) shall be permitted to serve as a wet vent for a bathroom group. Only one wet-vented fixture drain or trap arm shall discharge upstream of the dry-vented fixture drain connection. Dry vent connections to the horizontal wet vent shall be in accordance with Section 905.2 and Section

  905.3.

  908.2.2 Size. The wet vent shall be sized based on the fixture unit discharge into the wet vent. The wet vent shall be not less than 2 inches (50 mm) in diameter for 4 drainage fixture units (dfu) or less, and not less than 3 inches (80 mm) in diameter for 5 dfu or more. The dry vent shall be sized in accordance with Table 702.1 and Table 703.2 based on the total fixture units discharging into the wet vent.

  908.2.3 Trap Arm. The length of the trap arm shall not exceed the limits in Table 1002.2. The trap size shall be in accordance with Section 1003.3. The vent pipe opening from the horizontal wet vent, except for water closets and similar fixtures, shall not be below the weir of the trap.

• CPC § 911.3 Medium relevance — show source text

  911.3 Relief Vent . . . . . . . . . . . . . . . . . .192

  911.4 Slope and Size of Horizontal Branch . . . . . . . . . . . . . . . . . . . . .192

  911.5 Additional Fixtures . . . . . . . . . . . .192

  912.0 Engineered Vent System . . . . . . .192

  912.1 General . . . . . . . . . . . . . . . . . . . . .192

  912.2 Minimum Requirements . . . . . . . .192

  CHAPTER 10 TRAPS AND

  INTERCEPTORS . . . . . . . . . . . . .193

  1001.0 General . . . . . . . . . . . . . . . . . . . . .195

  1001.1 Applicability . . . . . . . . . . . . . . . . . .195

  1001.2 Where Required . . . . . . . . . . . . . .195

  1002.0 Traps Protected by Vent Pipes . .195

  1002.1 Vent Pipes . . . . . . . . . . . . . . . . . .195

  1002.2 Fixture Traps . . . . . . . . . . . . . . . .195

  1002.3 Change of Direction . . . . . . . . . . .195

  1002.4 Vent Pipe Opening . . . . . . . . . . . .195

  1003.0 Traps – Described . . . . . . . . . . . .195

  1003.1 General Requirements . . . . . . . . .195

  Table 1002.2 Horizontal Lengths of Trap Arms . . . . . . . . . . . . . . . . . . . . . . .195

  1003.2 Slip Joint Fittings . . . . . . . . . . . . .195

  1003.3 Size . . . . . . . . . . . . . . . . . . . . . . . .195

  1004.0 Traps . . . . . . . . . . . . . . . . . . . . . .196

  1004.1 Prohibited . . . . . . . . . . . . . . . . . . .196

  1004.2 Movable Parts . . . . . . . . . . . . . . . .196

  1005.0 Trap Seals . . . . . . . . . . . . . . . . . .196

  1005.1 General . . . . . . . . . . . . . . . . . . . . .196

  1006.0 Floor Drain Traps . . . . . . . . . . . . .196

  1006.1 General . . . . . . . . . . . . . . . . . . . . .196

  1007.0 Trap Seal Protection . . . . . . . . . . .196

  1007.1 General . . . . . . . . . . . . . . . . . . . . .196

  1007.2 Trap Seal Primers . . . . . . . . . . . .196

  1008.0 Building Traps . . . . . . . . . . . . . . . .196

  1008.1 General . . . . . . . . . . . . . . . . . . . . .196

• CPC § 1002.2 Medium relevance — show source text

  1002.2 Fixture Traps. Each fixture trap shall have a protecting vent so located that the developed length of the trap arm from the trap weir to the inner edge of the vent shall be within the distance given in Table 1002.2 but in no case less than two times the diameter of the trap arm. 1002.3 Change of Direction. A trap arm shall be permitted to change direction without the use of a cleanout where such change of direction does not exceed 90 degrees (1.57 rad). Horizontal changes in the direction of trap arms shall be in accordance with Section 706.3.

  Exception: For trap arms, 3 inches (80 mm) in diameter and larger, the change of direction shall not exceed 135 degrees (2.36 rad) without the use of a cleanout. 1002.4 Vent Pipe Opening. The vent pipe opening from soil or waste pipe, except for water closets and similar fixtures, shall not be below the weir of the trap.

  1003.0 Traps – Described. 1003.1 General Requirements. Each trap, except for traps within an interceptor or similar device shall be selfcleaning. Traps for bathtubs, showers, lavatories, sinks, laun

  dry sinks, floor drains, urinals, drinking fountains, dental units, and similar fixtures shall be of standard design, weight and shall be of ABS, cast-brass, cast-iron, lead, PP, PVC, or other approved material. An exposed and readily accessible drawn-copper alloy tubing trap, not less than 17 B & S Gauge (0.045 inch) (1.143 mm), shall be permitted to be used on fixtures discharging domestic sewage.

  Exception s :

  (1) Drawn-copper alloy tubing traps shall not be used for urinals. Each trap shall have the manufacturer’s name stamped legibly in the metal of the trap, and each tubing trap shall have the gauge of the tubing in addition to the manufacturer’s name. A trap shall have a smooth and uniform interior waterway.

  (2) [HCD 1 & HCD 2] Non-water supplied urinals conform- ing to ASME A112.19.19-2016, Standard for Vitreous China Nonwater Urinals, or reference standards in Table 1701.1 for non-vitreous ceramic or plastic urinal fixtures.

  TABLE 1002.2

  HORIZONTAL LENGTHS OF TRAP ARMS (EXCEPT FOR WATER CLOSETS AND SIMILAR FIXTURES) [1, 2, 3]

  TRAP ARM PIPE DIAMETER (inches)	DISTANCE TRAP TO VENT MINIMUM (inches)	LENGTH MAXIMUM (inches)
  11⁄4	21⁄2	30
  11⁄2	3	42
  2	4	60
  3	6	72
  4	8	120
  Exceeding 4	2 x Diameter	120

  For SI units: 1 inch = 25.4 mm

• CPC § 1501.7 Medium relevance — show source text

  Residential,
  and Commercial Use|Water Quality|1501.7, 1506.8,
  1506.10.2, 1603.4| |IAPMO IGC 325-2016|Oil/Water Separators Performance|Interceptors|Table 1009.1| |IAPMO PS 53-2020|Grooved Mechanical Pipe Couplings and Grooved Fittings|Fittings|Table 604.1| |IAPMO PS 65-2019a|Airgap Units for Water Conditioning Equipment Installation|Backflow Protection|611.2| |IAPMO PS 66-2015|Dielectric Fittings|Fittings|605.15, 605.16.1,
  605.16.3| |IAPMO PS 72-2019|Valves with Atmospheric Vacuum Breakers|Valves|603.5.6(5)| |IAPMO PS 76-2021|Trap Primers for Fill Valves and Flushometer Valves|DWV Components|1007.2| |IAPMO PS 80-2019|Clarifiers|Interceptors|Table 1009.1| |IAPMO PS 90-2014|Elastomeric Test Caps, Cleanout Caps, and Combination Test
  Caps/Shielded Couplings|DWV Components|Table 707.2| |IAPMO PS 104-2019|Pressure Relief Connection for Dispensing Equipment|Valves|603.5.22(1)| |IAPMO PS 106-2015el|Tileable Shower Receptors and Shower Kits|Fixtures|408.2| |IAPMO PS 117-2021|Press Connections|Fittings|Table 604.1| |CSA B45.5-2017/IAPMO
  Z124-2017|Plastic Plumbing Fixtures (with Errata dated August 2017)|Fixtures|407.1, 408.1, 409.1,
  411.1, 412.1, 420.1| |IAPMO/ANSI Z124.5-
  2013e1 (R2018)|Plastic Toilet Seats|Appurtenance|411.3| |CSA B45.11-2017/IAPMO
  Z401-2017 (R2021)|Glass Plumbing Fixtures|Fixtures|407.1| |CSA B45.12-2013/IAPMO
  Z402-2013 (R2018)|Aluminum and Copper Plumbing Fixtures|Fixtures|407.1, 408.1, 409.1,
  420.1| |CSA B45.8-2018/IAPMO
  Z403-2018|Terrazzo, Concrete, Composite Stone, and Natural Stone
  Plumbing Fixtures|Fixtures|407.1, 420.1|

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  REFERENCED STANDARDS

  TABLE 1701.1 (continued) REFERENCED STANDARDS

  STANDARD NUMBER	STANDARD TITLE	APPLICATION	REFERENCED SECTION
  IAPMO/ANSI Z601-2018	Scale Reduction Devices	Water Conditioning, Water Treatment	611.1.2
  ANSI/CAN/IAPMO Z1001- 2021	Prefabricated Gravity Grease Interceptors	Fixtures	Table 1009.1, 1014.1,

• CPC § 408.4.2 Medium relevance — show source text

  4, 408.4.2(1)| |ASSE 1018-2001 (R2021)|Trap Seal Primer Valves - Potable Water Supplied|Valves|1007.2| |ASSE 1019-2011 (R2016)|Wall Hydrant with Backflow Protection and Freeze Resistance|Backflow Protection|Table 603.2| |ASSE 1020-2020|Pressure Vacuum Breaker Assemblies|Backflow Protection|Table 603.2| |ASSE 1022-2021|Backflow Preventer for Beverage Dispensing Equipment|Backflow Protection|Table 603.2,
  603.5.12| |ASSE 1023-2020|Electrically Heated or Cooled Water Dispensers|Appliances|417.6| |ASSE 1024-2017 (R2021)|Dual Check Backflow Preventers|Backflow Protection|Table 603.2, 603.5.12| |ASSE 1032-2004 (R2021)|Dual Check Valve Type Backflow Preventers for Carbonated
  Beverage Dispensers, Post Mix Type|Backflow Protection|603.5.12| |ASSE 1035-2020|Laboratory Faucet Backflow Preventers|Backflow Protection|Table 603.2,
  603.3.11| |ASSE 1037-2020/ASME
  A112.1037-2020/CSA
  B125.37-2020|Pressurized Flushing Devices for Plumbing Fixtures|Backflow Protection|413.2| |ASSE 1044-2015 (R2020)|Trap Seal Primer - Drainage Types and Electric Design Types|DWV Components|1007.2| |ASSE 1047-2021|Reduced Pressure Detector Backflow Prevention Assemblies|Backflow Protection|Table 603.2| |ASSE 1048-2021|Double Check Detector Backflow Prevention Assemblies|Backflow Protection|Table 603.2| |ASSE 1052-2016|Hose Connection Backflow Preventers|Backflow Protection|Table 603.2| |ASSE 1053-2019|Dual Check Backflow Preventer Wall Hydrants – Freeze
  Resistant Type|Backflow Protection|Table 603.2| |ANSI/CAN/ASSE/IAPMO
  1055-2020|Chemical Dispensers with Integral Backflow Protection|Backflow Protection|Table 603.2,
  603.5.22(1)| |ASSE 1056-2013 (R2021)|Spill Resistant Vacuum Breaker Assemblies|Backflow Protection|Table 603.2| |ASSE 1057-2012|Freeze Resistant Sanitary Yard Hydrants with Backflow Pro-
  tection|Backflow Protection|Table 603.2| |ASSE 1060-2017|Outdoor Enclosures for Fluid Conveying Components with
  Errata dated February 1, 2019|Miscellaneous|603.4.7| |ASSE 1061-2020|Push-Fit Fittings|Fittings|Table 604.1,
  605.1.3.3, 605.2.1.1,
  605.3.2.1, 605.9.3| |ASSE 1062-2017 (R2021)|Temperature Actuated, Flow Reduction (TAFR) Valves for
  Individual Supply Fittings|Valves|408.4.3, 417.

• CPC § 603.2 Medium relevance — show source text

  3, Table 603.2| |ASSE 1003-2020e2|Water Pressure Reducing Valves for Potable Water Distribution
  Systems|Valves|608.2| |ASSE 1004-2017|Commercial Dishwashing Machines|Backflow Protection|414.2| |ASSE 1008-2020|Plumbing Aspects of Residential Food Waste Disposer Units|Appliances|419.1| |ASSE 1010-2004|Water Hammer Arresters|Appliances|609.11| |ASSE 1011-2017|Hose Connection Vacuum Breakers|Backflow Protection|Table 603.2|

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  REFERENCED STANDARDS

  TABLE 1701.1 (continued) REFERENCED STANDARDS

  STANDARD NUMBER	STANDARD TITLE	APPLICATION	REFERENCED SECTION
  ASSE 1012-2009	Backflow Preventers with an Intermediate Atmospheric Vent	Backflow Protection	Table 603.2
  ASSE 1013-2021	Reduced Pressure Principle Backflow Prevention Assemblies	Backflow Protection	Table 603.2
  ASSE 1014-2020	Backflow Prevention Devices for Hand-Held Showers	Backflow Protection	417.3
  ASSE 1015-2021	Double Check Backflow Prevention	Backflow Protection	Table 603.2
  ASSE 1016-2017/ASME A112.1016-2017/CSA B125.16-2017	Automatic Compensating Valves for Individual Showers and Tub/Shower Combinations	Valves	408.4, 408.4.2(1)
  ASSE 1018-2001 (R2021)	Trap Seal Primer Valves - Potable Water Supplied	Valves	1007.2
  ASSE 1019-2011 (R2016)	Wall Hydrant with Backflow Protection and Freeze Resistance	Backflow Protection	Table 603.2
  ASSE 1020-2020	Pressure Vacuum Breaker Assemblies	Backflow Protection	Table 603.2
  ASSE 1022-2021	Backflow Preventer for Beverage Dispensing Equipment	Backflow Protection	Table 603.2, 603.5.12
  ASSE 1023-2020	Electrically Heated or Cooled Water Dispensers	Appliances	417.6
  ASSE 1024-2017 (R2021)	Dual Check Backflow Preventers	Backflow Protection	Table 603.2, 603.5.12
  ASSE 1032-2004 (R2021)	Dual Check Valve Type Backflow Preventers for Carbonated Beverage Dispensers, Post Mix Type	Backflow Protection	603.5.12
  ASSE 1035-2020	Laboratory Faucet Backflow Preventers	Backflow Protection	Table 603.2, 603.3.11
  ASSE 1037-2020/ASME A112.1037-2020/CSA B125.37-2020	Pressurized Flushing Devices for Plumbing Fixtures	Backflow Protection	413.2
  ASSE 1044-2015 (R2020)	Trap Seal Primer - Drainage Types and Electric Design Types	DWV Components	1007.

• CPC § 814.3.1 Medium relevance — show source text

  Condensate drain sizing for other slopes or other conditions shall be approved by the Authority Having Jurisdiction.

  Air-conditioning waste pipes, 1¼ of an inch (32 mm) and larger in size, shall be constructed of materials specified in Chapter 7. Condensate waste piping less than 1¼ of an inch (32 mm) in size shall be permitted to be PVC, CPVC, PE, PP, copper, or other rigid materials approved by the Authority Having Jurisdiction.

  814.3.1 Cleanouts. Condensate drain lines shall be configured or provided with a cleanout to permit the clearing of blockages and for maintenance without requiring the drain line to be cut. 814.4 Appliance Condensate Drains. Condensate drain lines from individual condensing appliances shall be sized as required by the manufacturer’s instructions. Condensate drain lines serving more than one appliance connecting to a common indirect waste pipe shall have the connections to the indirect waste pipe protected by a sanitary waste valve complying with ASME A112.18.8, condensate trap complying with IAPMO IGC 196, or trap with a trap primer. 814.5 Point of Discharge. Air-conditioning condensate waste pipes shall connect indirectly to the drainage system through an air gap or air break to trapped and vented receptors, dry wells, mop sinks, leach pits, or the tailpiece of plumbing fixtures. An individual condensate drain shall be trapped in accordance with the appliance manufacturer’s instructions or in accordance with Section 814.4.

  TABLE 814.3

  MINIMUM CONDENSATE PIPE SIZE

  For SI units: 1 ton of refrigerant = 3.52 kW, 1 inch = 25 mm

  For SI units: °C = (°F-32)/1.8

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  INDIRECT WASTES

  814.6 Condensate Waste from Air-Conditioning Coils. Where the condensate waste from air-conditioning coils discharges by direct connection to a lavatory tailpiece or to an approved accessible inlet on a bathtub overflow, the connection shall be located in the area controlled by the same person controlling the air-conditioned space. 814.7 Plastic Fittings. Female plastic screwed fittings shall be used with male plastic fittings and plastic threads.

  2025 CALIFORNIA PLUMBING CODE 185

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  CALIFORNIA PLUMBING CODE – MATRIX ADOPTION TABLE

  CHAPTER 9 - VENTS

  (Matrix Adoption Tables are non-regulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)

• CPC § 223.0 Medium relevance — show source text

  Trap Arm. Those portions of a fixture drain between a trap and the vent.

  Trap Primer. A device and system of piping that maintains a water seal in a remote trap. Trap Seal. The vertical distance between the crown weir and the top dip of the trap. Crown Weir (Trap Weir). The lowest point in the cross-section of the horizontal waterway at the exit of the trap. Top Dip (of the trap). The highest point in the internal cross-section of the trap at the lowest part of the bend (inverted siphon). By contrast, the bottom dip is the lowest point in the internal cross-section. Treated Gray Water. [BSC-CG & HCD 1] Nonpotable water meeting the definition of “gray water” collected and treated on-site suitable for direct beneficial use.

  223.0 – U –

  UPC. [HCD 1] “UPC” is the latest edition of the Uniform Plumbing Code, published by the International Association of Plumbing and Mechanical Officials. Unsanitary. See Insanitary.

  User Outlet. See Station Outlet.

  2025 CALIFORNIA PLUMBING CODE 43

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  DEFINITIONS

  224.0 – V –

  Vacuum. A pressure less than that exerted by the atmosphere.

  Vacuum Breaker. See Backflow Preventer.

  Vacuum Relief Valve. A device that prevents excessive vacuum in a pressure vessel. Vacuum System-Level 1. A system consisting of central vacuum-producing equipment with pressure and operating controls, shutoff valves, alarm warning systems, gauges, and a network of piping extending to and terminating with suitable station inlets at locations where patient suction could be required. Valve, Balancing. A valve that regulates and controls the return of water to the water heater in a recirculating hot water piping system. Valve, Isolation. A valve that isolates one piece of equipment from another.

  Valve, Pressure-Relief. A pressure-actuated valve held closed by a spring or other means and designed automatically to relieve pressure in excess of its setting.

  Valve, Riser. A valve at the base of a vertical riser that isolates that riser.

  Valve, Service. A valve is serving horizontal piping extending from a riser to a station outlet or inlet. Valve, Source. A single valve at the source that controls a number of units that makes up the source. Valve, Zone. A valve that controls the gas or vacuum to a particular area. Vent. See Plumbing Vent; Dry Vent; Wet Vent. Vent Connector, Gas. That portion of a gas venting system that connects a listed gas appliance beginning at the draft hood or flue collar to a gas vent and is installed entirely within the space or area in which the appliance is located. Vent Offset. An arrangement of two or more fittings and pipe installed for the purpose of locating a vertical section of vent pipe in a different but parallel plane with respect to an adjacent section of vertical vent pipe. [NFPA 54:3.3.101] Vent Pipe. See Plumbing Vent. **Vent Stack.

• CPC § 1502.3.2. Medium relevance — show source text

  (2) A potable water supply may be connected temporarily for the initial cross-connection test of the on-site treated non- potable gray water system as provided in Section 1502.3.2. 1506.5 Water Pressure. On-site treated non-potable gray water systems supplying water to water closets, urinals, and trap primers shall be capable of delivering not less than 15 pounds-force per square inch (psi) (103 kPa) residual pressure at the highest and most remote outlet served. Where the

  TABLE 1505.16 MINIMUM RECLAIMED (RECYCLED) WATER SOURCE TESTING, INSPECTION, AND MAINTENANCE FREQUENCY

  DESCRIPTION MINIMUM FREQUENCY*

  Inspect and clean filters and screens, and replace (where necessary). [Every 3 months.]

  Inspect pumps and verify operation. After initial installation and every 12 months thereafter.

  Inspect valves and verify operation. After initial installation and every 12 months thereafter.

  Inspect pressure tanks and verify operation. After initial installation and every 12 months thereafter.

  Clear debris from and inspect storage tanks, locking devices, and verify operation.

  After initial installation and every 12 months thereafter.

  Inspect caution labels and marking. After initial installation and every 12 months thereafter.

  * Note: Frequency is as described in this table, or more frequently as required by manufacturer’s instructions and/or the Authority Having Jurisdiction.

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  ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS

  1506.10.3 Deactivation and Drainage. The on-site treated nonpotable gray water system and the potable water system within the building shall be provided with the required appurtenances (e.g., valves, air/vacuum relief valves, etc.) to allow for deactivation or drainage as required for a cross-connection test in accordance with Section 1502.3.

  1506.10.4 Near Underground Potable Water Pipe. On-site treated nonpotable gray water pipes shall be permitted to be run or laid in the same trench as potable water pipes with a 12 inch (305 mm) minimum vertical and horizontal separation where both pipe materials are approved for use within a building. Where piping materials do not meet this requirement the minimum separation shall be increased to 60 inches (1524 mm). The potable water piping shall be installed at an elevation above the on-site treated nonpotable gray water piping. 1506.10.5 Required Filters. A filter permitting the passage of particulates no larger than 100 microns (100 µm) shall be provided for on-site treated nonpotable gray water supplied to water closets, urinals, trap primers, and drip irrigation system s . 1506.10.6 Disinfection. Where the intended use of onsite treated nonpotable gray water requires disinfec- tion and/or other treatment, on-site treated nonpotable gray water shall be disinfected as needed to ensure the required water quality is obtained at the point of use. Where chlorine is used for disinfection or treatment, water shall be tested for residual chlorine in accordance with ASTM D1253.

• CPC § 2-23 Medium relevance — show source text

  [RB] TERMITE-RESISTANT MATERIAL. Pressure-preservative-treated wood in accordance with the AWPA standards in Section R304.1, naturally durable termite-resistant wood, steel, concrete, masonry or other approved material.

  TESTING AGENCY. An agency approved by the department as qualified and equipped for testing of products, materials, equipment and installations in accordance with nationally recognized standards. For additional information, see Health and Safety Code Section 17920(m).

  [MP] THIRD-PARTY CERTIFICATION AGENCY. An approved agency operating a product or material certification system that incorporates initial product testing, assessment and surveillance of a manufacturer’s quality control system.

  [MP] THIRD-PARTY CERTIFIED. Certification obtained by the manufacturer indicating that the function and performance characteristics of a product or material have been determined by testing and ongoing surveillance by an approved third-party certification agency. Assertion of certification is in the form of identification in accordance with the requirements of the third-party certification agency.

  TODDLER. Any child between 18 months and 36 months of age.

  [RB] TOWNHOUSE. A building that contains three or more attached townhouse units.

  2025 CALIFORNIA RESIDENTIAL CODE 2-23

  on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

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  DEFINITIONS

  [RB] TOWNHOUSE UNIT. A single-family dwelling unit in a townhouse that extends from foundation to roof and that has a yard or public way on not less than two sides.

  [MP] TRAP. A fitting, either separate or built into a fixture, that provides a liquid seal to prevent the emission of sewer gases without materially affecting the flow of sewage or wastewater through it.

  [MP] TRAP ARM. That portion of a fixture drain between a trap weir and the vent fitting.

  [MP] TRAP PRIMER. A device or system of piping to maintain a water seal in a trap, typically installed where infrequent use of the trap would result in evaporation of the trap seal, such as floor drains.

  [MP] TRAP SEAL. The trap seal is the maximum vertical depth of liquid that a trap will retain, measured between the crown weir and the top of the dip of the trap.

  [RB] TRIM. Picture molds, chair rails, baseboards, handrails, door and window frames, and similar decorative or protective materials used in fixed applications.

  [RB] TRUSS DESIGN DRAWING. The graphic depiction of an individual truss, that describes the design and physical characteristics of the truss.

  [RB] TUBULAR DAYLIGHTING DEVICE (TDD). A nonoperable fenestration unit primarily designed to transmit daylight from a roof surface to an interior ceiling via a tubular conduit. The basic unit consists of an exterior glazed weathering surface, a light-transmitting tube with a reflective interior surface, and an interior-sealing device such as a translucent ceiling panel. The unit may be factory assembled, or field assembled from a manufactured kit.

  [MP] TYPE L VENT. A listed and labeled vent conforming to UL 641 for venting oil-burning appliances listed for use with Type L vents or with gas appliances listed for use with Type B vents.

• CPC § 1004.2 Medium relevance — show source text

  1004.2 Movable Parts. Bladders, check valves or another type of devices with moveable parts shall be prohibited to serve as a trap.

  1005.0 Trap Seals. 1005.1 General. Each fixture trap shall have a liquid seal of not less than 2 inches (51 mm) and not more than 4 inches (102 mm), except where a deeper seal is found necessary by the Authority Having Jurisdiction. Traps shall be set true with respect to their liquid seals and, where necessary, they shall be protected from freezing.

  1006.0 Floor Drain Traps. 1006.1 General. Floor drains shall connect into a trap so constructed that it can be readily cleaned and of a size to serve efficiently the purpose for which it is intended. The drain inlet shall be so located that it is in full view. Where subject to the reverse flow of sewage or liquid waste, such drains shall be equipped with an approved backwater valve.

  1007.0 Trap Seal Protection. 1007.1 General. Floor drain or similar traps directly connected to the drainage system and subject to infrequent use shall be protected with a trap seal primer, except where not deemed necessary for safety or sanitation by the Authority Having Jurisdiction. Trap seal primers shall be accessible for maintenance.

  1007.2 Trap Seal Primers. Potable water supply trap seal primer valves shall comply with ASSE 1018. Drainage or electronic design type trap seal primer devices shall comply with ASSE 1044 or IAPMO PS 76.

  1008.0 Building Traps. 1008.1 General. Building traps shall not be installed except where required by the Authority Having Jurisdiction. Each building trap where installed shall be provided with a cleanout and with a relieving vent or fresh-air intake on the inlet side of the trap, which needs not be larger than one-half the diameter of the drain to which it connects. Such relieving vent or fresh-air intake shall be carried above grade and terminate in a screened outlet located outside the building.

  1009.0 Interceptors (Clarifiers) and Separators.

  1009.1 Where Required. Interceptors (clarifiers) (including grease, oil, sand, solid interceptors, etc.) shall be required

  by the Authority Having Jurisdiction where they are necessary for the proper handling of liquid wastes containing grease, flammable wastes, sand, solids, acid or alkaline substances, or other ingredients harmful to the building drainage system, the public or private sewer, or to public or private sewage disposal. A list of acceptable interceptor standards is referenced in Table 1009.1.

  TABLE 1009.1 APPROVED INTERCEPTORS (CLARIFIERS)