CPC · California Plumbing Code
How must piping, fittings, fixtures and devices be marked and identified?
The CPC requires that every length of pipe, fitting, fixture, and device used in plumbing be permanently marked by the manufacturer with the markings required by its referenced standard and the manufacturer’s name; weight/quality must be shown when the standard requires it, field markings are not allowed, and the AHJ may require additional identification. (§301.2.1)
Last reviewed: July 6, 2026
What the code requires — plain English
Each length of pipe and every fitting, trap, fixture, material, and device used in a plumbing system must be cast, stamped, or indelibly marked with the markings required by the applicable referenced standard and the manufacturer’s mark or name, so the manufacturer can be readily identified. Where an approved standard requires it, products must also be marked with weight and quality. All marking must be performed by the manufacturer; field markings are not acceptable, and materials must be marked in a manner satisfactory to the Authority Having Jurisdiction. See § 301.2.1.
The single most important rule: every pipe length and plumbing product must carry the marks the approved standard requires plus the manufacturer’s name/mark; if the standard requires weight or quality, those must be on the product too (manufacturer-applied only). § 301.2.1.
Requirements in detail
Who and what is covered
- Each length of pipe and each pipe fitting, trap, fixture, material, and device used in a plumbing system must be marked. § 301.2.1.
- The code applies to items entering into plumbing construction unless the code or an AHJ grants approval otherwise. § 301.2.
What must appear on the product
- The product must display:
- Any markings required by the applicable referenced standard and listing agency, and
- The manufacturer’s mark or name that readily identifies the manufacturer to the end user.
- If the applicable standard requires it, the product must also show weight and quality. § 301.2.1.
Who must apply the marking
- Marking shall be done by the manufacturer. Field markings shall not be acceptable. The marking must be in a permanent form—cast, stamped, or indelibly marked. § 301.2.1.
How the Authority Having Jurisdiction (AHJ) fits in
- Materials and devices must be marked and identified in a manner satisfactory to the AHJ. The AHJ may require submittal for approval of items not otherwise provided for in the code. § 301.2 and § 301.2.1.
Exceptions & special markings called out elsewhere in the CPC
- The CPC contains specific marking requirements for particular systems that supplement § 301.2.1. Examples:
- Potable vs. nonpotable water systems are identified by color/legend and visible marking intervals (e.g., every 20 feet) — see § 601.3.
- Fuel gas piping must be marked as required by its referenced standard (e.g., polyethylene gas pipe marked “gas” and the ASTM designation) — see § 1208.5.4.
- Copper tubing must have incised marking and be marked in accordance with ASTM standards and color coding for types (Type K/L/M/DWV) — see § 903.2.3.
Quick decision table
| Item | Required marking / identification | Typical form | Code Reference |
|---|---|---|---|
| Each length of pipe | Markings required by referenced standard + manufacturer’s mark/name | Cast, stamped, or indelible | § 301.2.1 |
| Fittings, traps, fixtures, devices | Same as above; weight/quality if standard requires | Cast, stamped, or indelible | § 301.2.1 |
| Field-applied marks | Not acceptable | N/A | § 301.2.1 |
| Manufacturer responsibility | Manufacturer must mark product | N/A | § 301.2.1 |
| Nipples cut & threaded from approved pipe | Exempt from marking | N/A — Exception in § 301.2.1 | § 301.2.1 (Exception) |
| Potable / nonpotable ID (color & legend) | Color background, wording, direction of flow; visible every 20 ft or once per room | Paint, wraps, bands | § 601.3 |
| Fuel-gas plastic pipe | Marked “gas” and ASTM designation (where applicable) | Indelible marking | § 1208.5.4 |
| Copper tubing types | Incised marking + ASTM marking; color coding for Types K, L, M, DWV | Incised and colored marking | § 903.2.3 |
Exceptions & special cases
- Exception in § 301.2.1: Markings are not required on nipples created from cutting and threading of approved pipe. That is the only explicit general marking exception in § 301.2.1.
- The AHJ may require submittal or permit deviations for materials not otherwise provided for; materials must still be marked in a manner satisfactory to the AHJ. § 301.2.
- For specific product categories (gas piping, potable vs nonpotable systems, copper types, ground-loop systems) follow the additional marking rules in the applicable sections listed elsewhere in this code (examples above).
Common mistakes
- Relying on field-applied paint/labels instead of manufacturer-applied cast, stamped, or indelible marks — field markings are explicitly not acceptable. § 301.2.1.
- Installing unmarked items on the assumption “it’s obvious” — absence of the manufacturer’s mark or required standard markings can make products noncompliant and subject to rejection by the AHJ. § 301.2.1.
- Overlooking product-specific marking rules (for example, gas piping must show “gas” and the ASTM designation; potable vs nonpotable systems have color/legend and spacing rules). Check the specific sections such as § 1208.5.4 and § 601.3.
- Assuming small cut nipples need marking — remember the explicit exception that nipples cut and threaded from approved pipe need not be marked. § 301.2.1 (Exception).
Worked example — applying the rule with numbers
Scenario: You are the plumbing contractor installing a new water distribution system that uses lengths of factory-manufactured CPVC pressure pipe supplied in 10-foot lengths and a header of 50 feet composed of five joined lengths.
- Requirement: Each individual length of pipe (each factory 10‑ft piece) must bear the markings required by the applicable referenced standard plus the manufacturer’s mark or name, and any weight/quality marking if required by that standard. This marking must be cast, stamped, or indelibly marked by the manufacturer. You must not apply field markings yourself. § 301.2.1.
- If the system includes an alternate-water source (e.g., reclaimed or graywater) instead of potable water, the piping must also follow the color/legend and marking frequency (for example, identifying legend and color every 20 feet or at least once per room) specified in § 601.3. That means on a 50‑ft header you would need at least 3 visible identification locations (at 0 ft, ~20 ft, and ~40 ft) per the potable/nonpotable marking rule. § 601.3.
- If a run includes a short nipple cut and threaded from an approved pipe on site, that nipple is the explicit exception and need not be re-marked. § 301.2.1 (Exception).
Related provisions (select CPC sections)
- § 301.2 — Minimum standards; listing and AHJ approval requirements.
- § 301.2.1 — Marking (controlling section for this topic).
- § 601.3 — Identification of potable and nonpotable water systems (colors, wording, and marking spacing).
- § 1208.5.4 — Marking requirements for fuel gas plastic pipe (e.g., “gas” and ASTM designation).
- § 903.2.3 — Marking and color coding for copper tubing types.
- § 1708.3 — Ground-loop system marking requirements (labeling where piping enters a building).
Code references
Grounded in the retrieved California Plumbing Code — click a citation to read the verbatim passage:
CPC § 301.2 High relevance — show source text
301.2 Minimum Standards. Pipe, pipe fittings, traps, fixtures, material, and devices used in a plumbing system shall be listed (third-party certified) by a listing agency (accredited conformity assessment body) as complying with the approved applicable recognized standards referenced in this code, and shall be free from defects. Unless otherwise provided for in this code, materials, fixtures, or devices used or entering into the construction of plumbing systems, or parts thereof shall be submitted to the Authority Having Jurisdiction for approval prior to being installed. 301.2.1 Marking. Each length of pipe and each pipe fitting, trap, fixture, material, and device used in a plumbing system shall have cast, stamped, or indelibly marked on it any markings required by the applicable referenced standards and listing agency, and the manufacturer’s mark or name, which shall readily identify the manufacturer to the end user of the product. Where required by the approved standard that applies, the product shall be marked with the weight and the quality of the product. Materials and devices used or entering into the construction of plumbing and drainage systems, or parts thereof shall be marked and identified in a manner satisfactory to the Authority Having Jurisdiction. Such marking shall be done by the manufacturer. Field markings shall not be acceptable.
Exception: Markings shall not be required on nipples created from cutting and threading of approved pipe.
301.2.2 Standards. Standards listed or referred to in this chapter or other chapters cover materials that will conform to the requirements of this code, where used in accordance with the limitations imposed in this or other chapters thereof and their listing. Where a standard covers materials of various grades, weights, quality, or configurations, the portion of the listed standard that is applicable shall be used. Design and materials for special conditions or materials not provided for herein shall be permitted to be used by special permission of the Authority Having Jurisdiction after the Authority Having Jurisdiction has been satisfied as to their adequacy. A list of plumbing standards that appear in specific sections of this code is referenced in Table 1701.1. Standards referenced in Table 1701.1 shall be applied as indicated in the applicable referenced section. A list of additional approved standards, publications, practices, and guides that are not referenced in specific sections of this code appear in Table 1701.2. An IAPMO Installation Standard is referenced in Appendix I for the convenience of the users of this code. It is not considered as a part of this code unless formally adopted as such by the Authority Having Jurisdiction.
301.2.3 Plastic Pipe, Plastic Pipe Fittings, and Components. Plastic pipe, plastic pipe fittings, and components other than those for gas shall comply with NSF/ANSI 14.
301.2.4 Cast-Iron Soil Pipe, Fittings, and Hubless Couplings. Cast-iron soil pipe, fittings, and hubless couplings shall be third party certified in accordance with ASTM C1277 and CISPI 310 for couplings and ASTM A888, ASTM A74, and CISPI 301 for pipes and fittings. 301.2.5 Existing Buildings. In existing buildings or premises in which plumbing installations are to be altered, repaired, or renovated, the Authority Having Jurisdiction has discretionary powers to permit deviation from the provisions of this code, provided that such proposal to deviate is first submitted for proper determination in order that health and safety requirements, as they pertain to plumbing, shall be observed.
CPC § 301.3.1 High relevance — show source text
3
301.3.1
301.3.1.1
301.3.1.2
301.4.1
301.7
301.8
303.1_Exception_
304.1_Exception_
310.11
310.12
310.13
310.14
310.15
311.1_ Note_
312.2
312.7
312.11
313.8
321.0
322.0
323.0
||||||||||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.
2025 CALIFORNIA PLUMBING CODE 47
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48 2025 CALIFORNIA PLUMBING CODE
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CHAPTER 3
GENERAL REGULATIONS
301.0 General.
301.1 Applicability. This chapter shall govern the general requirements, not specific to other chapters, for the installation of plumbing systems. 301.2 Minimum Standards. Pipe, pipe fittings, traps, fixtures, material, and devices used in a plumbing system shall be listed (third-party certified) by a listing agency (accredited conformity assessment body) as complying with the approved applicable recognized standards referenced in this code, and shall be free from defects. Unless otherwise provided for in this code, materials, fixtures, or devices used or entering into the construction of plumbing systems, or parts thereof shall be submitted to the Authority Having Jurisdiction for approval prior to being installed. 301.2.1 Marking. Each length of pipe and each pipe fitting, trap, fixture, material, and device used in a plumbing system shall have cast, stamped, or indelibly marked on it any markings required by the applicable referenced standards and listing agency, and the manufacturer’s mark or name, which shall readily identify the manufacturer to the end user of the product. Where required by the approved standard that applies, the product shall be marked with the weight and the quality of the product. Materials and devices used or entering into the construction of plumbing and drainage systems, or parts thereof shall be marked and identified in a manner satisfactory to the Authority Having Jurisdiction. Such marking shall be done by the manufacturer. Field markings shall not be acceptable.
Exception: Markings shall not be required on nipples created from cutting and threading of approved pipe.
301.2.2 Standards. Standards listed or referred to in this chapter or other chapters cover materials that will conform to the requirements of this code, where used in accordance with the limitations imposed in this or other chapters thereof and their listing. Where a standard covers materials of various grades, weights, quality, or configurations, the portion of the listed standard that is applicable shall be used.
CPC § 0.293 High relevance — show source text
automatic storage
30 to 40 gallon tank
Water heater, automatic storage
50 gallon tank
Water heater, automatic instantaneous
Capacity at 2 gallons per minute
Capacity at 4 gallons per minute
Capacity at 6 gallons per minute
Water heater, domestic, circulating or
side-arm|
35 000
50 000
142 800
285 000
428 400
35 000| |
Cooking Appliances
Range, freestanding, domestic
Built-in oven or broiler unit, domestic
Built-in top unit, domestic|
65 000
25 000
40 000| |
Other Appliances
Refrigerator
Clothes dryer, Type 1 (domestic)
Gas fireplace direct-vent
Gas log
Barbecue
Gaslight|
3000
35 000
40 000
80 000
40 000
2500|For SI units: 1000 British thermal units per hour = 0.293 kW
1208.3.2 Sizing Methods. Gas piping shall be sized in accordance with one of the following:
(1) Pipe sizing tables or sizing equations in this chap ter.
(2) Sizing tables included in a listed piping system manufacturer’s installation instructions.
(3) Engineering methods. [NFPA 54:5.3.3]
1208.3.3 Allowable Pressure Drop. The design pressure loss in a piping system from the point of delivery to
TABLE 1208.3.1
APPROXIMATE GAS INPUT FOR
TYPICAL APPLIANCES
[NFPA 54: TABLE A.5.3.2.1]
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For SI units: 1000 British thermal units per hour = 0.293 kW
2025 CALIFORNIA PLUMBING CODE 217
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FUEL GAS PIPING
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1208.5.4 Plastic Pipe, Tubing, and Fittings. Polyethylene plastic pipe, tubing, and fittings used to supply fuel gas shall conform to ASTM D2513. Pipe to be used shall be marked “gas” and “ASTM D2513.” Polyamide pipe, tubing, and fittings shall be identified in and conform to ASTM F2945. Pipe to be used shall be marked “gas” and “ASTM F2945.” Polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (CPVC) plastic pipe, tubing, and fittings shall not be used to supply fuel gas. [NFPA 54:5.5.4.1.1 – 5.5.4.1.3]
1208.5.5 Regulator Vent Piping. Plastic pipe and fittings used to connect regulator vents to remote vent terminations shall be PVC (Schedule 40 and 80). PVC vent piping shall not be installed indoors. {NFPA 54:5.5.4.2}
CPC § 23500-3 High relevance — show source text
7_| |ANSI/AAMI/ISO 23500-3|Preparation and Quality Management of Fluids for
Haemodialysis and Related Therapies—Part 3: Water for
Haemodialysis and Related Therapies.|Miscellaneous|614.7| |ARCSA|ARCSA|ARCSA|ARCSA| |ARCSA/ASPE/ANSI 63-
2020|Rainwater Catchment Systems|Miscellaneous|1602.1| |ASME|ASME|ASME|ASME| |ASME A112.1.2-2012
(R2017)|Air Gaps in Plumbing Systems (For Plumbing Fixtures and
Water-Connected Receptors)|Fittings|Table 603.2| |ASME A112.1.3-2000
(R2019)|Air Gap Fittings for Use with Plumbing Fixtures, Appliances,
and Appurtenances|Fittings|Table 603.2| |ASME A112.3.1-2007
(R2017)|Stainless Steel Drainage Systems for Sanitary DWV, Storm,
and Vacuum Applications, Above- and Below-Ground|Piping|418.1, Table 701.2,
705.7.2, 1102.1| |ASME A112.3.4-2018/CSA
B45.9-2018
|Macerating Toilet Systems and Waste-Pumping Systems for
Plumbing Fixtures|Fixtures|710.13| |ASME A112.4.1-2009
(R2019)|Water Heater Relief Valve Drain Tubes|Appliances|608.5(2)| |ASME A112.4.2-2021/CSA
B45.16-2021|Personal Hygiene Devices for Water Closets|Fixtures|411.4| |ASME A112.4.4-2017|Plastic Push-Fit Drain, Waste, and Vent (DWV) Fittings|Fittings|Table 701.2| |ASME A112.4.14-
2017/CSA B125.14-2017|Manually Operated Valves for Use in Plumbing Systems|Valves|606.1| |ASME A112.6.1M-1997
(R2017)|Floor-Affixed Supports for Off-the-Floor Plumbing Fixtures
for Public Use|Fixtures|402.4| |ASME A112.6.2-2017|Framing-Affixed Supports (Carriers) for Off-the-Floor Plumb-
ing Fixtures|Fixtures|402.4| |ASME A112.6.3-2019|Floor and Trench Drains|Fixtures|418.1| |ASME A112.6.4-2003
(R2012)|Roof, Deck, and Balcony Drains|Fixtures|1102.1| |ASME A112.6.7-2010
(R2019)|Sanitary Floor Sinks|Fixtures|421.1| |ASME A112.6.9-2005
(R2019)|Siphonic Roof Drains|DWV Components|1106.3| |ASME A112.14.1-2003
(R2017)|Backwater Valves|Valves|710.6| |ASME A112.14.CPC § 301.3 High relevance — show source text
MANUFACTURED/MOBILE
HOME PARKS AND
RECREATIONAL VEHICLE PARKS . . . . . . . .Appendix E MARKINGS . . . . . . . . . . . . . . . . . . . . . . .(see Identification)
MATERIALS
Alternate . . . . . . . . . . . . . . . . . . . . . . . . .301.3, H 501.13
Approval required . . . . . . . . . . . . . . . . . . . . . . . . . .301.2 Approved standards . . . . . . . . . . . . . . . . . . . . . .301.2.2 Backwater, gate, or ball valves . . . . . . . . . . . . . . .710.6 Building drains . . . . . . . . . . . . . . . . . . . . . . .Table 701.2 Building sewers . . . . . . . . . . . .Table 701.2, 715.1, 720.0 Cesspools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .H 801.0
Cleanouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .707.1
Drainage piping, joints, and fittings . . . . . . . . . . . . . . . . . . .701.2, Table 701.2, 701.3, 705.0
Fuel gas piping, joints, and fittings . . . . . . . . . . . . . . . . . . . .1208.5, 1208.5.1,
1208.5.3 – 1208.5.4,
1208.5.9, 1208.5.10, 1208.5.11
Marking of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .301.2.1 Medical gas and medical vacuum . . . . . . . . . . . .1318.0 Potable water piping, joints, and fittings . . . . . . . . . . . . . . . . . . . .604.0, 605.0 Rainwater catchment system . . . . . .1602.7, Appendix K Septic tanks . . . . . . . . . . . . . . . . . . . . . . . . . . . .H 501.3 Storm drainage pipe . . . . . . . . . . . . . . . . . . . . . . .1101.4
Subsoil drain . . . . . . . . . . . . . . . . . . . . . . . . . . .1101.4.6
CPC § 1708.2 Medium relevance — show source text
(6) Ground-heat exchanger and building piping, valves, and operating controls, shall be set, adjusted, and operating as required.
(7) The system shall be labeled at the loop charging valves with a permanent-type label, indicating the type of heat transfer fluid used. Where antifreeze is used, the labels shall indicate the antifreeze type and concentration.
(8) Supply and return lines, as well as associated isolation valves from individual boreholes or water wells, shall be identified and tagged.
(9) Supply and return lines on submerged systems shall be identified in an approved manner, at the point of entry to a surface water resource.
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1708.2 Operation and Maintenance Manual. An operation and maintenance manual for the geothermal system shall be provided to the owner. The manual shall include information on required testing and maintenance of the system. Training shall be provided on the system’s operation, maintenance requirements, and on the content of the operation and maintenance manual. The operation and maintenance manual shall contain a layout of the ground-heat exchanger and building loop.
1708.3 Labeling and Marking. Ground source heat pump ground-loop system piping shall be marked with tape, metal tags, or other methods where it enters a building. The marking shall indicate the following words: “GROUND SOURCE HEAT PUMP-LOOP SYSTEM.” The marking shall indicate antifreeze used in the system by name and concentration.
1708.4 Documentation. The ground source heat pump system as-built installation drawings and instructions shall be provided to the building owner or designated agent.
1708.5 Maintenance. The periodic maintenance required, in accordance with the design requirements, shall be provided and be made available to the owner or designated agent.
1708.6 Records. The ground source heat pump system construction documents shall be provided to the owner.
1708.7 System Start-Up. System start-up shall be in accordance with ANSI/ CSA/IGSHPA C448 and Section 1708.0.
1708.8 Contaminants. Particulate contaminants shall be removed from the indoor piping system prior to initial start up.
1709.0 Decommissioning and Abandonment. 1709.1 General. Decommissioning of geothermal systems shall comply with ANSI/ CSA/IGSHPA C448. Prior to the abandonment or decommissioning of geothermal systems, the owner shall obtain the necessary permits from the Authority Having Jurisdiction.
Part II – Closed-Loop Systems.
1710.0 General.
1710.1 Applicability. Part II of this chapter shall apply to geothermal closed-loop systems such as, but not limited to, building systems coupled with a closed-loop system using water-based fluid as a heat transfer medium.
1710.2 Piping and Tubing. Piping and tubing for closedloop systems shall be in accordance Section 1703.2 and Table 1703.2.
1710.3 Borehole Piping and Tubing. Borehole piping or tubing for vertical and horizontally drilled closed-loop systems shall have a minimum wall thickness equal to SDR-11 and shall have a minimum pressure rating of not less than 160 psi (1103 kPa) at 73°F (23°C).
CPC § 1208.3.1 Medium relevance — show source text
TABLE 1208.3.1
APPROXIMATE GAS INPUT FOR
TYPICAL APPLIANCES
[NFPA 54: TABLE A.5.3.2.1]
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For SI units: 1000 British thermal units per hour = 0.293 kW
2025 CALIFORNIA PLUMBING CODE 217
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FUEL GAS PIPING
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1208.5.4 Plastic Pipe, Tubing, and Fittings. Polyethylene plastic pipe, tubing, and fittings used to supply fuel gas shall conform to ASTM D2513. Pipe to be used shall be marked “gas” and “ASTM D2513.” Polyamide pipe, tubing, and fittings shall be identified in and conform to ASTM F2945. Pipe to be used shall be marked “gas” and “ASTM F2945.” Polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (CPVC) plastic pipe, tubing, and fittings shall not be used to supply fuel gas. [NFPA 54:5.5.4.1.1 – 5.5.4.1.3]
1208.5.5 Regulator Vent Piping. Plastic pipe and fittings used to connect regulator vents to remote vent terminations shall be PVC (Schedule 40 and 80). PVC vent piping shall not be installed indoors. {NFPA 54:5.5.4.2}
1208.5.6 Anodeless Risers. Anodeless risers shall
comply with Section 1208.5.6.1 through Section 1208.5.6.3.
1208.5.6.1 Factory-Assembled Anodeless Risers. Factory-assembled anodeless risers shall be recommended by the manufacturer for the gas used and shall be leak tested by the manufacturer in accordance with written procedures. [NFPA 54:5.5.4.3(1)]
1208.5.6.2 Service Head Adapters and Field- Assembled Anodeless Risers. Service head
adapters and field-assembled anodeless risers incorporating service head adapters shall be recommended by the manufacturer for the gas used and shall be design-certified to meet the requirements of Category I of ASTM D2513 and 49 CFR 192.281(e). The manufacturer shall provide the user qualified installation instructions as prescribed by 49 CFR 192.283(b).
[NFPA 54:5.5.4.3(2)]
1208.5.6.3 Undiluted Liquefied Petroleum Gas Piping. The use of plastic pipe, tubing, and fittings in undiluted LP-Gas piping systems shall be in accordance with NFPA 58. [NFPA 54:5.5.4.3(3)]
CPC § 601.2.1.1 Medium relevance — show source text
601.2.1.1 Approved Submeters. [HCD 1] Sub- meters (or meters) shall be approved in accordance with the Business and Professions Code, Division 5.
601.2.1.2 Submeter Testing. [HCD 1] Submeter (or meter) testing shall be in accordance with the California Code of Regulations, Title 4, Division 9, Chapter 3, Article 1; Civil Code, Division 3, Part 4, Title 5; and Business and Professions Code, Divi- sion 5.
601.2.2 Hot and Cold Water Required. In occupancies where plumbing fixtures are installed for private use, hot water shall be required for bathing, washing, laundry, cooking purposes, dishwashing or maintenance. In occupancies where plumbing fixtures are installed for public use, hot water shall be required for bathing and washing purposes. This requirement shall not supersede the requirements for individual temperature control limitations for public lavatories and public and private bidets, bathtubs, whirlpool bathtubs, and shower control valves.
601.3 Identification of a Potable and Nonpotable Water System. In buildings where potable water and nonpotable water systems are installed, each system shall be clearly identified in accordance with Section 601.3.1 through Section 601.3.5.
601.3.1 Potable Water. Green background with white lettering.
601.3.2 Color and Information. Each system shall be identified with a colored pipe or band and coded with paints, wraps, and materials compatible with the piping.
Except as required by Section 601.3.3, nonpotable water systems shall have a yellow background with black uppercase lettering, with the words “CAUTION: NONPOTABLE WATER, DO NOT DRINK.” Each nonpotable system shall be identified to designate the liquid being conveyed, and the direction of normal flow shall be clearly shown. The minimum size of the letters and length of the color field shall comply with Table 601.3.2.
[HCD 1 & HCD 2] An international symbol of a glass in a circle with a slash through it shall be provided sim- ilar to that shown in Figure 601 for all nonpotable water
systems.
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WATER SUPPLY AND DISTRIBUTION
FIGURE 601
INTERNATIONAL SYMBOL
The background color and required information shall be indicated every 20 feet (6096 mm) but not less than once per room, and shall be visible from the floor level.
601.3.3 Alternate Water Sources. Alternate water source systems shall have a purple (Pantone color No. 512, 522C, or equivalent) background with uppercase lettering and shall be field or factory marked as follows:
(1) Gray water systems shall be marked in accordance with this section with the words “CAUTION: NONPOTABLE GRAY WATER, DO NOT DRINK” in black letters.
California Plumbing Code Medium relevance — show source text
2
5
10
15|36
38
51
NA
NA|93
69
63
NA
NA|57
47
44
39
NA|56
57
75
95
NA|190
136
128
116
NA|111
93
86
79
72|80
80
102
128
158|325
225
216
201
186|186
149
140
131
124|116
115
144
182
220|499
337
326
308
290|283
224
217
203
192|153
148
182
228
272|713
473
459
438
418|388
314
298
284
269| |20|0
2
5
10
15
20|35
37
50
NA
NA
NA|96
74
68
NA
NA
NA|60
50
47
41
NA
NA|54
56
73
93
NA
NA|200
148
140
129
NA
NA|118
99
94
86
80
NA|78
78
100
125
155
186|346
248
239
223
208
192|201
165
158
146
136
126|114
113
141
177
216
254|537
375
363
344
325
306|306
248
239
224
210
196|149
144
178
222
264
309|772
528
514
491
469
448|428
344
334
316
301
285| |30|0
2
5CPC § 604.1 Medium relevance — show source text
(19 mm)
through 3 in. (76 mm), for Water Service|Piping|Table 604.1| |AWWA C904-2016|Crosslinked Polyethylene (PEX) Pressure Tubing,1⁄2 in.
through 3 in. (13 mm through 76 mm), for Water Service|Piping|Table 604.1| |AWWA C907-2017|Injection-Molded Polyvinyl Chloride (PVC) Pressure Fittings,
4 in. through 12 in. (100 mm through 300 mm), for Water,
Wastewater, and Reclaimed Water Service|Fittings|Table 604.1| |CFR|CFR|CFR|CFR| |49 CFR 192.281|Plastic Pipe|Plastic, Pipe|1208.5.6.2| |49 CFR 192.283|Plastic Pipe: Qualifying Joining Procedures|Plastic, Pipe|1208.5.6.2| |CGA|CGA|CGA|CGA| |CGA G-4.1-2018|Cleaning of Equipment for Oxygen Service|Miscellaneous|1318.2, 1321.8.7| |CGA M-1-2018|Medical Gas Supply Systems at Health Care Facilities|Miscellaneous|1324.5.7.3| |CGA V-5-2019|Diameter Index Safety System (Noninterchangeable Low Pres-
sure Connections for Medical Gas Applications)|Connections|1315.5| |CISPI|CISPI|CISPI|CISPI| |CISPI 301-2021|Hubless Cast Iron Soil Pipe and Fittings for Sanitary and Storm
Drain, Waste, and Vent Piping Applications|Piping, Ferrous|301.2.4, Table 701.2,
Table 707.2| |CISPI 310-2020|Couplings for Use in Connection with Hubless Cast Iron Soil
Pipe and Fittings for Sanitary and Storm Drain, Waste, and
Vent Piping Applications|Joints|301.2.4, 705.2.2| |CSA|CSA|CSA|CSA| |ASME A112.19.2-
2018/CSA B45.1-2018|Ceramic Plumbing Fixtures|Fixtures|407.1, 408.1, 409.1,
410.1, 411.1, 412.1,
415.1, 420.1| |ASME A112.19.1-
2018/CSA B45.2-2018|Enameled Cast Iron and Enameled Steel Plumbing Fixtures|Fixtures|407.1, 408.1, 409.1,
415.1, 420.1| |ASME A112.19.3-
2017/CSA B45.4-2017|Stainless Steel Plumbing Fixtures|Fixtures|407.1, 408.1, 409.1,
410.1, 411.1, 415.1,
420.1| |CSA B45.5-2017/IAPMO
Z124-2017|Plastic Plumbing Fixtures (with Errata dated August 2017)|Fixtures|407.1, 408.1, 409.1,CPC § 811.0. Medium relevance — show source text
defined in Section 811.0.
903.2.3 Marking. Copper or copper alloy tubing, in addition to the required incised marking, shall be marked in accordance with either ASTM B306 or ASTM B88. The colors shall be Type K, green; Type L, blue; Type M, red; and Type DWV, yellow. 903.3 Changes in Direction. Changes in the direction of vent piping shall be made by the appropriate use of approved fittings, and no such pipe shall be strained or bent. Burred ends shall be reamed to the full bore of the pipe.
904.0 Size of Vents.
904.1 Size. The size of vent piping shall be determined from its length and the total number of fixture units connected thereto, in accordance with Table 703.2. The diameter of an individual vent shall be not less than 1 [1] ⁄ 4 inches (32 mm) nor less than one-half the diameter of the drain to which it is connected. In addition, the drainage piping of each building and each connection to a public sewer or a private sewage disposal system shall be vented by means of one or more vent pipes, the aggregate cross-sectional area of which shall be not less than that of the largest required building sewer as determined from Table 703.2. Vent pipes from fixtures located upstream from pumps, ejectors, backwater valves, or other devices that obstruct the free flow of air and other gases between the building sewer and the outside atmosphere shall not be used for meeting the cross-sectional area venting requirements of this section. Exception: Where connected to a common building sewer, the drainage piping of two or more buildings located on the same lot and under one ownership shall be permitted to be vented by means of piping sized in accordance with Table 703.2, provided the aggregate cross-sectional area of vents is not less than that of the largest required common building sewer. 904.2 Length. Not more than one-third of the total permitted length, in accordance with Table 703.2, of a minimumsized vent shall be installed in a horizontal position. Where a minimum-sized vent is increased one pipe size for its entire length, the maximum length limitation shall not apply.
2025 CALIFORNIA PLUMBING CODE 189
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
VENTS
905.0 Vent Pipe Grades and Connections. 905.1 Grade. Vent and branch vent pipes shall be free from drops or sags, and each such vent shall be level or shall be so graded and connected as to drip back by gravity to the drainage pipe it serves. 905.2 Horizontal Drainage Pipe. Where vents connect to a horizontal drainage pipe, each vent pipe shall have its invert taken off above the drainage centerline of such pipe downstream of the trap being served. 905.3 Vent Pipe Rise. Unless prohibited by structural conditions, each vent shall rise vertically to a point not less than 6 inches (152 mm) above the flood-level rim of the fixture served before offsetting horizontally, and where two or more vent pipes converge, each such vent pipe shall rise to a point not less than 6 inches (152 mm) in height above the floodlevel rim of the plumbing fixture it serves before being connected to any other vent. Vents less than 6 inches (152 mm) above the flood-level rim of the fixture shall be installed with approved drainage fittings, material, and grade to the drain.
California Plumbing Code Medium relevance — show source text
3/8″
main reinforcement bars at 57/8″ pitch
with7/8″ concrete cover;3/8″ main rein-
forcement bars at 41/2″ pitch
perpendicular with1/2″ concrete cover;
13′1″ span restrained.|195 psf|4 hrs|||7|1, 7|4| |F/C-4-RC-7|4″|4″ (5025 psi) concrete deck;1/4″ reinforce-
ment bars at 71/2″ pitch with3/4″ cover;3/8″
main reinforcement bars at 33/4″ pitch
perpendicular with1/2″ cover; 13′1″ span
restrained.|140 psf|1 hr
16 min|||7|1, 2|11/4| |F/C-4-RC-8|4″|4″ thick (4905 psi) deck;1/4″ reinforce-
ment bars at 71/2″ pitch with7/8″ cover;3/8″
main reinforcement bars at 33/4″ pitch
perpendicular with1/2″ cover; 13′1″ span
restrained.|100 psf|1 hr
23 min|||7|1, 2|11/3| |F/C-4-RC-9|4″|4″ deep (4370 psi);1/4″ reinforcement bars
at 6″ pitch with3/4″ cover;1/4″ main rein-
forcement bars at 4″ pitch perpendicular
with1/2″ cover; 13′1″ span restrained.|150 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-10|4″|4″ thick (5140 psi) deck;1/4″ reinforce-
ment bars at 71/2″ pitch with7/8″ cover;3/8″
main reinforcement bars at 33/4″ pitch
perpendicular with1/2″ cover; 13′1″ span
restrained.|140 psf|1 hr
16 min|||7|1, 5|11/4| |F/C-4-RC-11|4″|4″ thick (4000 psi) concrete deck;
3″ × 11/2″ × 4 lbs R.S.J.; 2′6″ C.R.S.; flush
with top surface; 4″ × 6″ x 13 SWG mesh
reinforcement 1″ from bottom of slab; 6′6″
span restrained.|150 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-12|4″|4″ deep (2380 psi) concrete deck;
3″ × 11/2″ × 4 lbs R.S.J.; 2′6″ C.R.S.
Frequently asked questions
Who must apply the required markings?
The manufacturer must apply the marks (cast, stamped, or indelible). Field markings are not acceptable. See § 301.2.1.
Are cut nipples required to be marked?
No — the code explicitly exempts nipples created from cutting and threading approved pipe from the marking requirement. § 301.2.1 (Exception).
If a product standard requires a weight or grade marking, is that mandatory?
Yes — where the approved standard requires weight or quality marking, the product must be marked accordingly. § 301.2.1.
Can the AHJ require additional marking or accept alternate identification?
Yes — materials and devices must be marked in a manner satisfactory to the Authority Having Jurisdiction; the AHJ also reviews submittals for items not covered. § 301.2 and § 301.2.1.
How often must a nonpotable water pipe be labeled?
For nonpotable systems, marking (color and wording) must be visible every 20 feet and not less than once per room, per § 601.3.
More in California Plumbing Code
- Administration
- Definitions
- General Regulations
- Plumbing Fixtures and Fixture Fittings
- Water Heaters
- Water Supply and Distribution
- Sanitary Drainage (Drain, Waste, and Vent)
- Indirect Wastes
- Vents
- Traps and Interceptors
- Storm Drainage
- Fuel Gas Piping
- Health Care Facilities — Medical Gas and Medical Vacuum Systems
- Alternate Water Sources and Nonpotable Rainwater Catchment Systems
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