Chapter 6 — WATER SUPPLY AND DISTRIBUTION
604.1 Pipe, Tube, and Fittings.
California Plumbing Code (Title 24, Part 5) · 2025 edition · updated 2026-09-12 · California
Italicized text is a California amendment to the model code, as printed in the official publication.
Pipe, tube, fittings, solvent cement, thread sealants, solders, and flux used in potable water systems intended to supply drinking water shall comply with NSF/ANSI/CAN 61. Where pipe fittings and valves are made from copper alloys containing more than 15 percent zinc by weight and are used in plastic piping systems, they shall be resistant to dezincification and stress corrosion cracking in compliance with NSF/ANSI 14.
Materials used in the water supply system, except valves and similar devices, shall be of a like material, except where otherwise approved by the Authority Having Jurisdiction.
Materials for building water piping and building supply piping shall comply with the applicable standards referenced in Table 604.1.
Exception: [OSHPD 1, 2, 3, 4 & 5] Use of CPVC is not per- mitted for potable water applications. 604.1.1 Local Authority to Approve CPVC Pipe Within Residential Buildings Under Specified Con- ditions. [HCD 1 & HCD 2] The local responsible build- ing official of any city, county, or city and county, shall authorize by permit the use of CPVC for hot and cold water distribution systems within the interior of residential build- ings provided all of the following conditions are satisfied:
(a) Permit Conditions. Any building permit issued pur- suant to Section 604.1.1 shall be conditioned on compliance with the mitigation measures set forth in this section.
(b) Approved Materials. Only CPVC plumbing mate- rial listed as an approved material and installed in accordance with this code may be used.
(c) Installation and Use. Any installation and use of CPVC plumbing material pursuant to this section shall comply with all applicable requirements of this code and the manufacturer’s installation instructions.
(d) Certification of Compliance. Prior to issuing a building permit pursuant to Section 604.1.1, the building official shall require as part of the permit- ting process that the contractor, or the appropriate plumbing subcontractors, provide written certifica- tion: (1) that is required in subdivision (e), and (2) that he or she will comply with the flushing proce- dures and worker safety measures of this code and the manufacturer’s installation instructions.
(e) Worker Safety. Any contractor applying for a build- ing permit that includes the use of CPVC plumbing materials authorized pursuant to this section shall include in the permit application a signed written certification stating that:
(1) They are aware of the health and safety hazards associated with CPVC plumbing installations;
(2) They have included in their Injury and Illness Prevention Plan the hazards associated with CPVC plumbing pipe installations; and
(3) The worker safety training elements of their Injury and Illness Prevention Plan meet the Department of Industrial Relation’s guidelines.
(f) Findings of Compliance. The building official shall not give final permit approval of any CPVC plumbing materials installed pursuant to Section 604.1.1 unless he or she finds that the material has been installed in compliance with the requirements of this code and the manufacturer’s installation instructions.
(g) Penalties. Any contractor or subcontractor found to have failed to comply with the flushing, ventilation, and glove requirements of this code and the manu- facturer’s installation instructions shall be subject to the penalties in Health and Safety Code, Division 13, Part 1.5, Chapter 6 (Section 17995 et seq.). In addition, if during the conduct of any building inspection the building official finds that the venti- lation and glove requirements of this code, are being violated, such building officials shall cite the con- tractor or subcontractor for that violation.
(h) Special Requirements for CPVC Installation within Residential Structures. In addition to the other requirements in the California Plumbing Code, all installations of CPVC pipe within resi- dential structures shall meet the following:
(i) Flushing Procedures. All installations of CPVC pipe within residential structures shall be flushed twice over a period of at least one (1) week. The pipe system shall be first flushed for at least 10 minutes and then filled and allowed to stand for no less than 1 week, after which all the branches of the pipe system must be flushed long enough to fully empty the con- tained volume. At the time of the fill, each fix- ture shall have a removable tag applied stating:
“This new plumbing system was first filled on (date) by (name). The California Department of Housing and Community Development requires that the sys- tem be flushed after standing at least one week after the fill date specified above. If the system is used ear- lier than one week after the fill date, the water must be allowed to run for at least two minutes prior to use for human consumption. This tag may not be removed prior to flushing, except by the homeowner.”
(ii) Worker Safety Measures. Mechanical ventila- tion sufficient to maintain exposures below the relevant exposure limits established by state regulation shall be provided in enclosed spaces. This ventilation shall be directed at the breath- ing zone of the worker installing the pipe. Where mechanical ventilation is not practical, respirators, suitable for organic vapors, shall be used. For the purpose of this subdivision, an enclosed space is defined as:
(1) A space less than 100 square feet of floor area under a ceiling with a height of 10 feet or less, and which does not have openings (consisting of doors, windows, or unfin- ished walls) on at least two sides;
(2) Crawl spaces having a height of less than three feet;
146 2025 CALIFORNIA PLUMBING CODE
WATER SUPPLY AND DISTRIBUTION
(3) Enclosed attics that have a roof and ceil- ing; or
(4) Trenches having a depth greater than 24 inches.
Installers of CPVC pipe within residential struc- tures shall use non-latex thin gauge (4 millime- ters) nitrile gloves, or other gloves providing an equivalent or better degree of protection during the installation of the CPVC plumbing system. Gloves shall be provided to all workers by the contractor, or plumbing subcontractor, and shall be replaced upon contamination by cements.
604.1.2 PEX. [HCD 1 & HCD 2] All installations of PEX pipe where it is the initial plumbing piping installed in new construction shall be flushed twice over a period of at least one week. The pipe system shall be first flushed for at least 10 minutes and then filled and allowed to stand for no less than 1 week, after which all the branches of the pipe system must be flushed long enough to fully empty the contained volume. This provision shall not apply to the installation of PEX pipe where it replaces an existing pipe system of any material.
(1) At the time of fill, each fixture shall have a remov- able tag applied stating:
(a) “This new plumbing system was first filled and _flushed on ______ (date) by ____________ (name). The State of California requires that the system be flushed after standing at least one week after the fill date specified above. If this system is used earlier than one week after the fill date, the water must be allowed to run for at least two minutes prior to use for human con- sumption. This tag may not be removed prior to the completion of the required second flushing, except by the building owner or occupant.”
(2) Prior to issuing a building permit to install PEX pipe, the building official shall require as part of the permitting process that the contractor, or the appro- priate plumbing subcontractors, provide written cer- tification that he or she will comply with the flushing procedures set forth in the code.
(3) The building official shall not give final permit approval of any PEX plumbing installation unless he or she finds that the material has been installed in compliance with the requirements of the code, includ- ing the requirements to flush and tag the systems.
(4) Any contractor or subcontractor found to have failed to comply with the PEX flushing requirements shall be subject to the penalties in Health and Safety Code, Division 13, Part 1.5, Chapter 6 (Section 17995, et seq.).
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Ask AI about this code▸Contents — California Plumbing Code (Title 24, Part 5)
- Chapter 1 — GENERAL CODE PROVISIONS
- Chapter 2 — DEFINITIONS
- Chapter 3 — GENERAL REGULATIONS
- Chapter 4 — PLUMBING FIXTURES AND FIXTURE FITTINGS
- Chapter 5 — WATER HEATERS
▸Chapter 6 — WATER SUPPLY AND DISTRIBUTION
Overview- 601.1 Applicability.
- 601.2 Water Supply and Flushing.
- 601.3 Identification of a Potable and Nonpotable Water System.
- 601.4 Schools of Cosmetology and Cosmetological
- 601.5 Meat and Poultry Processing Plants.
- 601.6 Collection Centers and Facilities. [AGR]
- 601.7 Renderers. [AGR]
- 601.8 Horse Meat and Pet Food Establishments. [AGR]
- 602.1 Prohibited Installation.
- 602.2 Cross-Contamination.
- 602.3 Backflow Prevention.
- 602.4 Approval by Authority.
- 603.1 General.
- 603.2 Approval of Devices or Assemblies.
- 603.3 Backflow Prevention Devices, Assemblies, and Methods.
- 603.4 General Requirements.
- 603.5 Specific Requirements.
- 604.1 Pipe, Tube, and Fittings.
- 604.2 Lead Content.
- 604.3 Copper or Copper Alloy Tube.
- 604.4 Hard-Drawn Copper or Copper Alloy Tubing.
- 604.5 Flexible Connectors.
- 604.6 Cast-Iron Fittings.
- 604.7 Malleable Iron Fittings.
- 604.8 Previously Used Piping and Tubing.
- 604.9 Epoxy Coating.
- 604.10 Plastic Materials.
- 604.11 Solder.
- 604.12 Flexible Corrugated Connectors.
- 604.13 Water Heater Connectors.
- 605.1 Copper or Copper Alloy Pipe, Tubing,
- 605.2 CPVC Plastic Pipe and Joints.
- 605.3 CPVC/AL/CPVC Plastic Pipe and Joints.
- 605.4 Ductile Iron Pipe and Joints.
- 605.5 Galvanized Steel Pipe and Joints.
- 605.6 PE
- 605.7 PE-AL-PE Plastic
- 605.8 PE-RT.
- 605.9 PEX
- 605.10 PEX-AL-PEX Plastic Tubing and Joints.
- 605.11 Polypropylene (PP) Piping and Joints.
- 605.12 PVC
- 605.13 Stainless Steel Pipe
- 605.14 Slip Joints.
- 605.15 Dielectric Unions.
- 605.16 Joints Between Various Materials.
- 606.1 General.
- 606.2 Fullway Valve.
- 606.3 Multidwelling Units.
- 606.4 Multiple Openings.
- 606.5 Control Valve.
- 606.6 Accessible.
- 606.7 Multiple Fixtures.
- 606.8 [OSHPD 1, 1R, 2, 3, 4 & 5]
- 606.9 Check Valve Required.
- 606.10 Leak Detection Devices.
- 607.1 General.
- 607.2 Private Well Water Tanks.
- 607.3 Potable Water Tanks.
- 607.4 Venting.
- 607.5 Overflow.
- 607.6 Valves.
- 608.1 Inadequate Water Pressure.
- 608.2 Excessive Water Pressure.
- 608.3 Expansion Tanks, and Combination Tempera-ture and Pressu…
- 608.4 Pressure Relief Valves.
- 608.5 Discharge Piping.
- 608.6 Water-Heating Devices.
- 608.7 Vacuum Relief Valves.
- 609.1 Installation.
- 609.2 Trenches.
- 609.3 Under Concrete Slab.
- 609.4 Testing.
- 609.5 Unions.
- 609.6 Location.
- 609.7 Abutting Lot.
- 609.8 Pumps.
- 609.9 Low-Pressure Cutoff Required on Booster Pumps for Water …
- 609.10 Disinfection of Potable Water System.
- 609.11 Water Hammer.
- 609.12 Pipe Insulation.
- 610.1 Size.
- 610.2 Pressure Loss.
- 610.3 Quantity of Water.
- 610.4 Sizing Water Supply and Distribution Systems.
- 610.5 Sizing per Appendices A, C,
- 610.6 Friction and Pressure Loss.
- 610.7 Conditions for Using Table 610.4.
- 610.8 Size of Meter and Building Supply Pipe Using Table 610.4.
- 610.9 Size of Branches.
- 610.10 Sizing for Flushometer Valves.
- 610.11 Sizing Systems for Flushometer Tanks.
- 610.12 Sizing for Velocity.
- 610.13 Exceptions.
- 611.1 Application.
- 611.2 Air Gap Discharge.
- 611.3 Connection Tubing.
- 611.4 Sizing of Residential Softeners.
- 612.1 Installation.
- 613.1 The domestic water-heating equipment and distribu-
- 613.2 At least two pieces of hot-water-heating equipment shall
- 613.3 Instantaneous heaters are permitted for supplying hot
- 613.4 Water storage tanks shall be fabricated of corrosion-
- 613.5 Temperature control valves shall be provided to auto-
- 613.6 Hot-water distribution system serving patient care areas
- 613.7 At fixtures where water exceeding 125°F (52°C) is acces-
- 613.8 Sectionalizing valves shall be provided as required by S…
- 613.9 Hot water distribution shall include test ports and valved
- 614.1 Dialysis water feedlines shall be CPVC (chlorinated
- 614.2 All piping for multistation or central dialysis units sh…
- 614.3 All valves shall be located in accessible locations.
- 614.4 Piping and valves shall be identified according to their…
- 614.5 A means of preventing backwashing or flushing of the
- 614.6 A continuous audible alarm shall sound at the nurses’
- 614.7 Water treatment equipment and water used for dialysis
- 614.8 A diagram of all piping as installed shall be posted at …
- 615.1 Uses Not Permitted.
- 615.2 [OSHPD 1, 1R, 2, 3, 4 & 5]
- 615.3 [OSHPD 1, 1R, 2, 3, 4 & 5]
- 616.1 For new acute care hospital buildings submitted after
- 616.2 The emergency supply of water shall be provided at ade-
- 616.3 Storage tank connections and circulation shall be
- Chapter 7 — SANITARY DRAINAGE
- Chapter 8 — INDIRECT WASTES
- Chapter 9 — VENTS
- Chapter 10 — TRAPS AND INTERCEPTORS
- Chapter 11 — STORM DRAINAGE
- Chapter 12 — FUEL GAS PIPING
- Chapter 13 — HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICA…
- Chapter 14 — FIRESTOP PROTECTION
- Chapter 15 — ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS
- Chapter 16 — NONPOTABLE RAINWATER CATCHMENT SYSTEMS
- Chapter 17 — REFERENCED STANDARDS
- Appendix A — RECOMMENDED RULES FOR SIZING THE WATER SUPPLY SYS…
- Appendix B — EXPLANATORY NOTES ON COMBINATION WASTE AND VENT S…
- Appendix C — ALTERNATE PLUMBING SYSTEMS
- Appendix D — SIZING STORM WATER DRAINAGE SYSTEMS
- Appendix E — MANUFACTURED/MOBILE HOME PARKS AND RECREATIONAL V…
- Appendix F — FIREFIGHTER BREATHING AIR REPLENISHMENT SYSTEMS
- Appendix G — SIZING OF VENTING SYSTEMS
- Appendix H — PRIVATE SEWAGE DISPOSAL SYSTEMS
- Appendix I — INSTALLATION STANDARDS
- Appendix J — COMBINATION OF INDOOR AND OUTDOOR COMBUSTION AND …
- Appendix K — POTABLE RAINWATER CATCHMENT SYSTEMS
- Appendix L — SUSTAINABLE PRACTICES
- Appendix M — PEAK WATER DEMAND CALCULATOR
- Appendix N — IMPACT OF WATER TEMPERATURE ON THE POTENTIAL FOR …
- Appendix O — NON-SEWERED SANITATION SYSTEMS
- Appendix P — PROFESSIONAL QUALIFICATIONS
- Appendix Q — INDOOR HORTICULTURAL FACILITIES
- Appendix R — TINY HOUSES
- Appendix S — ONSITE STORMWATER TREATMENT SYSTEMS