CPC · California Plumbing Code

Prohibited joints and fittings (flared, compression, push-fit, certain unions)

For medical gas and vacuum piping, California requires permanent, listed joints (brazed or equivalent). Do not use flared, compression, quick push‑fit, straight‑threaded unions, or pipe‑crimp closures in the distribution system; see §1322.7 and permitted alternatives in §1322.6.

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Last reviewed: July 6, 2026

What the code requires — plain English

For medical gas and medical vacuum distribution systems the California Plumbing Code forbids the use of flared, compression-type, straight‑threaded connections (including unions), pipe‑crimping as a permanent stop, and removable or nonremovable quick‑assembly push‑fit fittings anywhere in the distribution pipeline. The controlling rule is § 1322.7.

For medical gas/vacuum piping: use only permanent, code‑listed joining methods — do not use flared, compression, straight‑threaded unions, pipe‑crimping or quick push‑fit connectors. (See § 1322.7.)

Requirements in detail

Scope and purpose

  • The prohibition in § 1322.7 applies throughout medical gas and vacuum distribution pipeline systems — this is the system serving outlets/inlets, alarm device tubing, and other components.
  • The code requires permanent joints for medical gas service; other permitted joining methods must provide integrity similar to brazing (see § 1322.6).

What is prohibited (itemized)

  • Flared connections — including at station outlets and inlets. § 1322.7 (1).
  • Compression‑type connections — including to station outlets/inlets, alarm devices and other components. § 1322.7 (1).
  • Other straight‑threaded connections, including unions — straight‑thread connections and unions are expressly prohibited. § 1322.7 (2).
  • Pipe‑crimping tools used to permanently stop flow in medical gas/vacuum piping. § 1322.7 (3).
  • Removable and nonremovable quick‑assembly push‑fit fittings (those that use a quick push connector) — prohibited. § 1322.7 (4).

What is permitted as alternatives

  • Listed or approved metallic gas tube fittings that, when made up, provide a permanent joint having the mechanical, thermal, and sealing integrity of a brazed joint are permitted. See § 1322.6.
  • Specific joining methods allowed elsewhere in the chapter include brazed, welded, memory‑metal, and axially swaged fittings when they meet the code criteria and listing requirements (see Sections § 1321.x, § 1322.1–1322.4, and § 1322.6).
  • Threaded fittings are allowed only for a few limited uses (pressure and vacuum indicators, alarm device connections, gas‑specific demand check fittings, and source equipment on the source side of the source valve) and must be tapered ASME B1.20.1 threads with proper thread sealant applied only to male threads. See § 1322.5.

Quick reference table — decision‑relevant fitting types

Fitting / Joint type Allowed for medical gas/vacuum distribution? Code Reference
Flared connection No — prohibited § 1322.7 (1)
Compression connection No — prohibited § 1322.7 (1)
Straight‑threaded union / straight threads No — prohibited § 1322.7 (2)
Pipe crimping (to permanently stop flow) No — prohibited § 1322.7 (3)
Removable / nonremovable quick push‑fit connectors No — prohibited § 1322.7 (4)
Listed permanent metallic tube fittings (brazed‑equivalent integrity) Yes — permitted § 1322.6
Threaded fittings (limited uses: indicators, alarms, source‑side) Yes — restricted § 1322.5
Dielectric union / dielectric fitting (when required by equipment manufacturer) Conditionally permitted per requirements § 1322.6.1

Installation and workmanship expectations

  • Where permitted fittings are used they must meet the listed standard, be cleaned for oxygen service where required, and be installed per manufacturer instructions and applicable welding/brazing procedures in the chapter (see § 1321 and § 1322 series).

Exceptions & special cases

  • Dielectric fittings: A dielectric fitting is permitted only where required by the manufacturer of special medical equipment to electrically isolate equipment from system distribution piping. Such fittings must be brass or copper with an approved dielectric, may be a union, and must be cleaned for oxygen if used on oxygen lines (§ 1322.6.1).
  • Threaded fittings: Threaded joints are limited to indicators/alarms/demand‑check fittings and source‑side equipment and must follow § 1322.5 rules (tapered threads, PTFE or approved sealant applied to male threads only). These are not a general alternative to permanent joints in the distribution piping.
  • Note: Push‑fit and compression fittings are commonly allowed for potable water and many non‑medical applications (for example, push‑fit fittings are described in water piping chapters such as § 605.1.3.3 / § 605.1.3.2 and PEX push‑fit allowances elsewhere). Those allowances do not apply to medical gas/vacuum distribution systems — the medical gas chapter explicitly prohibits push‑fit and compression for medical gas service. Contrast § 1322.7 with the water/joining sections (e.g., § 605.1.3.3 and § 605.9.3) for other systems.

Common mistakes

  • Assuming push‑fit or compression fittings allowed in domestic plumbing are acceptable for medical gas systems. (They are explicitly prohibited in § 1322.7.)
  • Installing unions or other straight‑threaded connections at outlets or inlets instead of permanently brazed or listed permanent fittings. § 1322.7 (2) prohibits this.
  • Using pipe‑crimping tools as a “permanent” closure method on medical gas lines; the code forbids this method. § 1322.7 (3).
  • Failing to follow the limited threaded‑connection exceptions in § 1322.5 and over‑using threaded joints where not allowed.
  • Overlooking the dielectric‑fitting constraints: dielectric fittings are only permitted when required by equipment manufacturers and must meet the § 1322.6.1 criteria.

Worked example — hospital oxygen drop to a patient outlet

Scenario: A contractor must install a drop to a patient oxygen station outlet. The drop is copper tubing sized for a station — the code requires drops to individual station outlets and inlets be not less than DN15 (NPS 1/2) (5/8 inch O.D.). § 1323.1.2.

  • Proposal A (non‑compliant): use a removable push‑fit connector to join the station outlet to the drop because it is faster.

    • Problem: The code prohibits push‑fit connectors in medical gas systems (§ 1322.7 (4)). Do not use this.

  • Correct approach (compliant): join the drop to the station outlet with a brazed joint or a listed metallic gas tube fitting that provides a permanent joint equal to a brazed joint, or use a manufacturer‑approved permanently assembled union only where permitted by the dielectric fitting exception (if required by the equipment manufacturer and meeting § 1322.6.1). Also ensure the drop meets the minimum DN15 / NPS 1/2 (5/8" O.D.) sizing per § 1323.1.2.

Step‑by‑step:

  1. Confirm drop size = DN15 (NPS 1/2) (5/8" O.D.) per § 1323.1.2.
  2. Specify either: (a) brazed copper socket per the brazing rules in § 1321, or (b) a listed metallic tube fitting that provides brazed‑equivalent permanent integrity per § 1322.6.
  3. Do not use compression, flared, push‑fit or straight‑thread unions at the station outlet — these are forbidden by § 1322.7.

Related provisions (quick links)

  • § 1322.6 — Other types of fittings permitted (listed metallic fittings providing brazed‑equivalent joints).
  • § 1322.6.1 — Dielectric fittings: conditions when permitted.
  • § 1322.5 — Threaded fittings: limited allowed uses and assembly requirements.
  • § 1321.x — Brazed joints and brazing requirements (chapter on brazing procedures).
  • § 1323.1.2 — Drops to individual station outlets and minimum sizing (DN15 / NPS 1/2 / 5/8" O.D.).
  • Water/plumbing chapters that allow push‑fit/compression for non‑medical piping for contrast (e.g., § 605.1.3.3 push‑fit for copper; § 605.9.3 push‑fit for PEX) — these illustrate that a fitting type allowed in general plumbing is explicitly disallowed for medical gas by § 1322.7.

If you want, I can:

  • Produce a short checklist for field installers to demonstrate compliance at each station outlet (what to inspect and record), or
  • Draft a sample specification paragraph for procurement that ensures only code‑permitted fittings are purchased and used.

Code references

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

  • CPC § 5.1.10.8 High relevance — show source text

    (3) They shall be made up with polytetrafluoroethylene (PTFE) tape or other thread sealant recommended for oxygen service, with sealant applied to the male threads only and care taken to ensure sealant does not enter the pipe. [NFPA 99:5.1.10.8] 1322.6 Other Types of Fittings. Listed or approved metallic gas tube fittings that, when made up, provide a permanent joint having the mechanical, thermal, and sealing integrity of a brazed joint shall be permitted to be used. [NFPA 99:5.1.10.9.1]

    1322.6.1 Dielectric Fittings. Dielectric fittings that comply with the following shall be permitted only where required by the manufacturer of special medical equipment to electrically isolate the equipment from the system distribution piping:

    (1) They shall be of brass or copper construction with an approved dielectric.

    (2) They shall be permitted to be a union.

    (3) They shall be clean for oxygen where used for medical gases and medical support gases. [NFPA 99:5.1.10.9.2]

    1322.7 Prohibited Joints. The following joints shall be prohibited throughout medical gas and vacuum distribution pipeline systems:

    (1) Flared and compression-type connections, including connections to station outlets and inlets, alarm devices, and other components.

    (2) Other straight-threaded connections, including unions.

    (3) Pipe-crimping tools used to permanently stop the flow of medical gas and vacuum piping.

    288 2025 CALIFORNIA PLUMBING CODE

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

    HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICAL VACUUM SYSTEMS

    (4) Removable and nonremovable push-fit fittings that employ a quick assembly push fit connector. [NFPA 99:5.1.10.10]

    1323.0 Installation of Piping and Equipment. 1323.1 Required Pipe Sizing. Piping systems shall be designed and sized to deliver the required flow rates at the utilization pressures. [NFPA 99:5.1.10.11.1.1]

  • CPC § 1322.6.1 High relevance — show source text

    1322.6.1 Dielectric Fittings. Dielectric fittings that comply with the following shall be permitted only where required by the manufacturer of special medical equipment to electrically isolate the equipment from the system distribution piping:

    (1) They shall be of brass or copper construction with an approved dielectric.

    (2) They shall be permitted to be a union.

    (3) They shall be clean for oxygen where used for medical gases and medical support gases. [NFPA 99:5.1.10.9.2]

    1322.7 Prohibited Joints. The following joints shall be prohibited throughout medical gas and vacuum distribution pipeline systems:

    (1) Flared and compression-type connections, including connections to station outlets and inlets, alarm devices, and other components.

    (2) Other straight-threaded connections, including unions.

    (3) Pipe-crimping tools used to permanently stop the flow of medical gas and vacuum piping.

    288 2025 CALIFORNIA PLUMBING CODE

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

    HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICAL VACUUM SYSTEMS

    (4) Removable and nonremovable push-fit fittings that employ a quick assembly push fit connector. [NFPA 99:5.1.10.10]

    1323.0 Installation of Piping and Equipment. 1323.1 Required Pipe Sizing. Piping systems shall be designed and sized to deliver the required flow rates at the utilization pressures. [NFPA 99:5.1.10.11.1.1]

    1323.1.1 Mains and Branches. Mains and branches in medical gas piping systems shall be not less than DN15 (NPS [1] ⁄ 2 ) ( [5] ⁄ 8 inch O.D.) size. Mains and branches in medical-surgical vacuum systems shall be not less than DN20 (NPS [3] ⁄ 4 ) ( [7] ⁄ 8 inch O.D.) size. [NFPA 99:5.1.10.11.1.2, 5.1.10.11.1.3] 1323.1.2 Drops to Individual Stations. Drops to individual station outlets and inlets shall be not less than DN15 (NPS [1] ⁄ 2 ) ( [5] ⁄ 8 inch O.D.) size. [NFPA 99:5.1.10.11.1.4] 1323.1.3 Runouts and Connecting Tubing. Runouts to alarm panels and connecting tubing for gauges and alarm devices shall be permitted to be DN8 (NPS [1] ⁄ 4 ) ( [3] ⁄ 8 inch O.D.) size. [NFPA 99:5.1.10.11.1.5]

    1323.1.4 Maximum Demand. Where the maximum demand for each medical gas or vacuum system does not exceed the values in Table 1323.1.4(1) through Table 1323.1.4(6), the size of pipe of each section of the system shall be determined in accordance with Section 1323.1.5. The size for systems beyond the range of Table 1323.1.4(1) through Table 1323.1.4(6) shall be determined in accordance with Section 1323.1.6.

  • CPC § 5.1.10.5.2.1 High relevance — show source text

    [NFPA 99:5.1.10.5.2.1]

    1322.2.1 Qualifications. Welders shall be qualified to Section IX of the ASME Boiler and Pressure Vessel Code. [NFPA 99:5.1.10.5.2.2]

    1322.3 Memory Metal Fittings. Memory metal fittings having a temperature rating not less than 1000°F (538°C) and a pressure rating not less than 300 psi (2068 kPa) shall be permitted to be used to join copper or stainless steel tube. Memory metal fittings shall be installed by qualified technicians in accordance with the manufacturer’s instructions. [NFPA 99:5.1.10.6.1, 5.1.10.6.2]

    1322.4 Axially Swaged Fittings. Axially swaged fittings providing metal-to-metal seals, suitable for service at 300 psig (2070 kPa) and able to withstand a temperature of 1000°F (538°C) and that, when complete, are permanent and nonseparable shall be permitted to be used to join copper or stainless steel tube. Axially swaged fittings shall be installed by qualified technicians in accordance with the manufacturer’s instructions. [NFPA 99:5.1.10.7.1, 5.1.10.7.2]

    1322.5 Threaded Fittings. Threaded fittings shall meet the following criteria:

    (1) They shall be limited to connections for pressure and vacuum indicators, alarm devices, gas-specific demand check fittings, and source equipment on the source side of the source valve.

    (2) They shall be tapered pipe threads complying with ASME B1.20.1.

    (3) They shall be made up with polytetrafluoroethylene (PTFE) tape or other thread sealant recommended for oxygen service, with sealant applied to the male threads only and care taken to ensure sealant does not enter the pipe. [NFPA 99:5.1.10.8] 1322.6 Other Types of Fittings. Listed or approved metallic gas tube fittings that, when made up, provide a permanent joint having the mechanical, thermal, and sealing integrity of a brazed joint shall be permitted to be used. [NFPA 99:5.1.10.9.1]

    1322.6.1 Dielectric Fittings. Dielectric fittings that comply with the following shall be permitted only where required by the manufacturer of special medical equipment to electrically isolate the equipment from the system distribution piping:

    (1) They shall be of brass or copper construction with an approved dielectric.

    (2) They shall be permitted to be a union.

    (3) They shall be clean for oxygen where used for medical gases and medical support gases. [NFPA 99:5.1.10.9.2]

    1322.7 Prohibited Joints. The following joints shall be prohibited throughout medical gas and vacuum distribution pipeline systems:

    (1) Flared and compression-type connections, including connections to station outlets and inlets, alarm devices, and other components.

    (2) Other straight-threaded connections, including unions.

    (3) Pipe-crimping tools used to permanently stop the flow of medical gas and vacuum piping.

    288 2025 CALIFORNIA PLUMBING CODE

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

  • CPC § 605.1.2 High relevance — show source text

    605.1.2 Flared Joints. Flared joints for soft copper or copper alloy water tubing shall be made with fittings that comply with the applicable standards referenced in Table 604.1. Pipe or tubing shall be cut square using an appropriate tubing cutter. The tubing shall be reamed to full inside diameter, resized to round, and expanded with a proper flaring tool.

    605.1.3 Mechanical Joints. Mechanical joints shall include, but are not limited to, compression, flanged, grooved, pressed, and push fit fittings. 605.1.3.1 Mechanically Formed Tee Fittings. Mechanically formed tee fittings shall have extracted collars that shall be formed in a continuous operation consisting of drilling a pilot hole and drawing out the pipe or tube surface to form a collar having a height not less than three times the thickness of the branch tube wall. The branch pipe or tube shall be notched to conform to the inner curve of the run pipe or tube and shall have two dimple depth stops to ensure that penetration of the branch pipe or tube into the collar is of a depth for brazing and that the branch pipe or tube does not obstruct the flow in the main line pipe or tube. Dimple depth stops shall be in line with the run of the pipe or tube. The second dimple shall be ¼ of an inch (6.4 mm) above the first and shall serve as a visual point of inspection. Fittings and joints shall be made by brazing. Soldered joints shall not be permitted. 605.1.3.2 Press-Connect Fittings. Press-connect fittings for copper or copper alloy pipe or tubing shall have an elastomeric o-ring that forms the joint. The pipe or tubing shall be fully inserted into the fitting, and the pipe or tubing marked at the shoulder of the fitting. Pipe or tubing shall be cut square, chamfered, and reamed to full inside diameter. The fitting alignment shall be checked against the mark on the pipe or tubing to ensure the pipe or tubing is inserted into the fitting. The joint shall be pressed using the tool recommended by the manufacturer. 605.1.3.3 Push Fit Fittings. Removable and nonremovable push fit fittings for copper or copper alloy tubing or pipe that employ quick assembly push fit connectors shall comply with ASSE 1061. Push fit fittings for copper or copper alloy pipe or tubing shall have an approved elastomeric o-ring that forms the joint. Pipe or tubing shall be cut square, chamfered, and reamed to full inside diameter. The tubing shall be fully inserted into the fitting, and the tubing marked at the shoulder of the fitting. The fitting alignment shall be checked against the mark on the tubing to ensure the tubing is inserted into the fitting and gripping mechanism has engaged on the pipe. 605.1.4 Soldered Joints. Soldered joints between copper or copper alloy pipe or tubing and fittings shall be made in accordance with ASTM B828 with the following sequence of joint preparation and operation as follows: measuring and cutting, reaming, cleaning, fluxing, assembly and support, heating, applying the solder, cooling and cleaning. Pipe or tubing shall be cut square and reamed to the full inside diameter including the removal of burrs on the outside of the pipe or tubing. Surfaces to be joined shall be cleaned bright by manual or mechanical means.

  • CPC § 18.6 High relevance — show source text

    ** Flexible metallic (copper and stainless steel), reinforced flexible, braided stainless steel, or polymer braided with EPDM core connectors that connect a water heater to the piping system shall comply with ASME A112.18.6/CSA B125.6. Copper, copper alloy, or stainless steel flexible connectors shall not exceed 24 inches (610 mm). PEX, PEX-AL-PEX, PE-AL-PE, or PE-RT tubing shall not be installed within the first 18 inches (457 mm) of piping connected to a water heater. [BSC, HCD 1 & HCD 2] PEX-AL-PEX is not adopted for use in potable water supply and distribution systems.

    605.0 Joints and Connections.

    605.1 Copper or Copper Alloy Pipe, Tubing, and Joints. Joining methods for copper or copper alloy pipe, tubing, and fittings shall be installed in accordance with the manufacturer’s installation instructions and shall comply with Section 605.1.1 through Section 605.1.5. 605.1.1 Brazed Joints. Brazed joints between copper or copper alloy pipe or tubing and fittings shall be made with brazing alloys having a liquid temperature above 1000°F (538°C). The joint surfaces to be brazed shall be cleaned bright by either manual or mechanical means. Tubing shall be cut square and reamed to full inside diameter. Brazing flux shall be applied to the joint surfaces where required by manufacturer’s recommendation. Brazing filler metal shall conform to AWS A5.8 and shall be applied at the point where the pipe or tubing enters the socket of the fitting. 605.1.2 Flared Joints. Flared joints for soft copper or copper alloy water tubing shall be made with fittings that comply with the applicable standards referenced in Table 604.1. Pipe or tubing shall be cut square using an appropriate tubing cutter. The tubing shall be reamed to full inside diameter, resized to round, and expanded with a proper flaring tool.

    605.1.3 Mechanical Joints. Mechanical joints shall include, but are not limited to, compression, flanged, grooved, pressed, and push fit fittings. 605.1.3.1 Mechanically Formed Tee Fittings. Mechanically formed tee fittings shall have extracted collars that shall be formed in a continuous operation consisting of drilling a pilot hole and drawing out the pipe or tube surface to form a collar having a height not less than three times the thickness of the branch tube wall. The branch pipe or tube shall be notched to conform to the inner curve of the run pipe or tube and shall have two dimple depth stops to ensure that penetration of the branch pipe or tube into the collar is of a depth for brazing and that the branch pipe or tube does not obstruct the flow in the main line pipe or tube. Dimple depth stops shall be in line with the run of the pipe or tube. The second dimple shall be ¼ of an inch (6.4 mm) above the first and shall serve as a visual point of inspection. Fittings and joints shall be made by brazing. Soldered joints shall not be permitted. 605.1.3.2 Press-Connect Fittings. Press-connect fittings for copper or copper alloy pipe or tubing shall have an elastomeric o-ring that forms the joint.

  • CPC § 605.6.2 Medium relevance — show source text

    605.6.2 Mechanical Joints. Mechanical joints between PE pipe or tubing and fittings shall include insert and mechanical compression fittings that provide a pressure seal resistance to pullout. Joints for insert fittings shall be made by cutting the pipe square, using a cutter designed for plastic piping, and removal of sharp edges. Two stainless steel clamps shall be placed over the end of the pipe. Fittings shall be checked for proper size based on the diameter of the pipe. The end of pipe shall be placed over the barbed insert fitting, making contact with the fitting shoulder. Clamps shall be positioned equal to 180 degrees (3.14 rad) apart and shall be tightened to provide a leak tight joint. Compression type couplings and fittings shall be permitted for use in joining PE piping and tubing. Stiffeners that extend beyond the

    clamp or nut shall be prohibited. Bends shall be not less than 30 pipe diameters, or the coil radius where bending with the coil. Bends shall not be permitted closer than 10 pipe diameters of a fitting or valve. Mechanical joints shall be designed for their intended use. 605.7 PE-AL-PE Plastic Pipe/Tubing and Joints. PEAL-PE plastic pipe or tubing and fitting joining methods shall be installed in accordance with the manufacturer’s installation instructions and shall comply with Section 605.7.1 and Section 605.7.1.1.

    605.7.1 Mechanical Joints. Mechanical joints for PEAL-PE pipe or tubing and fittings shall be either of the metal insert fittings with a split ring and compression nut or metal insert fittings with copper crimp rings. Metal insert fittings shall comply with ASTM F1974. Crimp insert fittings shall be joined to the pipe by placing the copper crimp ring around the outer circumference of the pipe, forcing the pipe material into the space formed by the ribs on the fitting until the pipe contacts the shoulder of the fitting. The crimp ring shall then be positioned on the pipe so the edge of the crimp ring is [1] ⁄ 8 of an inch (3.2 mm) to [1] ⁄ 4 of an inch (6.4 mm) from the end of the pipe. The jaws of the crimping tool shall be centered over the crimp ring and tool perpendicular to the barb. The jaws shall be closed around the crimp ring and shall not be crimped more than once. 605.7.1.1 Compression Joints. Compression joints for PE-AL-PE pipe or tubing and fittings shall be joined through the compression of a split ring, by a compression nut around the circumference of the pipe. The compression nut and split ring shall be placed around the pipe. The ribbed end of the fitting shall be inserted into the pipe until the pipe contacts the shoulder of the fitting. Position and compress the split ring by tightening the compression nut onto the insert fitting. 605.8 PE-RT. Polyethylene of raised temperature (PE-RT) tubing and fitting joining methods and shall comply with Section 605.8.1.

    605.8.1 Mechanical Joints. Fittings for PE-RT tubing shall comply with the applicable standards listed in Table 604.1. Mechanical joints for PE-RT tubing shall be installed in accordance with the manufacturer’s instal lation instructions.

  • CPC § 85-2019 Medium relevance — show source text

    Concrete Seepage Pit Liners and Covers|DWV Components| |IAPMO PS 85-2019|Tools for Mechanically Formed Tee Connections in Copper Tubing|Miscellaneous| |IAPMO PS 86-2019|Rainwater Diverter Valves for Non-Roofed Area Slabs|DWV Components| |IAPMO PS 91-2019|Plastic Stabilizers for Use with Plastic Closet Bends|DWV Components| |IAPMO PS 92-2013e1|Heat Exchangers and Indirect Water Heaters|Miscellaneous| |IAPMO PS 94-2012e1|Insulated Protectors for P-Traps, Supply Stops and Risers|Miscellaneous| |IAPMO PS 95-2018e3|Pipe Support Hangers and Hooks|DWV Components| |IAPMO PS 101-2019|Suction Relief Valves|Valves| |IAPMO PS 110-2019|PVC Cold Water Compression Fittings|Fittings| |IAPMO PS 111-2019|PVC Cold Water Gripper Fittings|Fittings| |IAPMO PS 112-2019|PVC Plastic Valves for Cold Water Distribution Systems Outside a Building and
    CPVC Plastic Valves for Hot and Cold Water Distribution Systems|Valves| |IAPMO PS 115-2019|Hot Water On-Demand or Automatic Activated Hot Water Pumping Systems|Miscellaneous| |IAPMO PS 119-2012ae3|Water-Powered Sump Pumps|Miscellaneous| |IAPMO/ANSI Z124.7-2013
    (R2018)|Prefabricated Plastic Spa Shells|Fixtures, Swimming
    Pools, Spas, and Hot
    Tubs| |IAPMO/ANSI Z124.8-
    2013e2 (R2018)|Plastic Liners for Bathtubs and Shower Receptors|Fixtures| |IAPMO/ANSI Z1000-2019|Prefabricated Septic Tanks|DWV Components| |ICC|ICC|ICC| |ASABE/ICC 802-2014|Landscape Irrigation Sprinkler and Emitter Standard|Irrigation| |ISO|ISO|ISO| |ANSI/CAN/IAPMO/ISO
    30500-2019|Non-Sewered Sanitation Systems - Prefabricated Integrated Treatment Units - General
    Safety and Performance Requirements for Design and Testing|Miscellaneous| |MSS|MSS|MSS| |MSS SP-25-2018|Standard Marking System for Valves, Fittings, Flanges, and Unions|Miscellaneous| |MSS SP-42-2013|Corrosion-Resistant Gate, Globe, Angle, and Check Valves with Flanged and Butt
    Weld Ends (Classes 150, 300, & 600)|Piping, Ferrous| |MSS SP-44-2019|Steel Pipeline Flanges|Fittings| |MSS SP-83-2018|Class 3000 and 6000 Pipe Unions, Socket Welding and Threaded (Carbon Steel,
    Alloy Steel, Stainless Steels, and Nickel Alloys)|Joints| |MSS SP-104-2018|Wrought Copper, Solder-Joint Pressure Fittings|Fittings| |MSS SP-106-2019|Cast Copper Alloy Flanges and Flanged Fittings: Class 125, 150, and 300|Fittings| |MSS SP-109-2018|Weld-Fabricated,

  • CPC § 605.8 Medium relevance — show source text

    Position and compress the split ring by tightening the compression nut onto the insert fitting. 605.8 PE-RT. Polyethylene of raised temperature (PE-RT) tubing and fitting joining methods and shall comply with Section 605.8.1.

    605.8.1 Mechanical Joints. Fittings for PE-RT tubing shall comply with the applicable standards listed in Table 604.1. Mechanical joints for PE-RT tubing shall be installed in accordance with the manufacturer’s instal lation instructions.

    605.9 PEX Plastic Tubing and Joints. PEX plastic tubing and fitting joining methods shall be installed in accordance with the manufacturer’s installation instructions and shall comply with Section 605.9.1 through Section 605.9.3.

    All PEX pipe installed in California must provide at least 30-day UV protection. [OSHPD 1, 1R, 2, 3, 4 & 5] Instal- lation and use of PEX tubing shall be in accordance with manufacturer’s standards. PEX piping shall not be used for any application that would result in noncompliance with any provisions of the California Building Standards Code. 605.9.1 Fittings. Fittings for PEX tubing shall comply with the applicable standards referenced in Table 604.1. PEX tubing that complies with ASTM F876 shall be marked with the applicable standard designation for the

    2025 CALIFORNIA PLUMBING CODE 151

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

    WATER SUPPLY AND DISTRIBUTION

    fittings, specified by the tubing manufacturer for use with the tubing. Brass fittings used with PEX tubing shall meet or exceed NSF/ANSI 14 standards to prevent dezincifi- cation and stress crack corrosion. [OSHPD 1, 1R, 2, 3, 4 & 5] Installation and use of PEX tubing shall be in accordance with manufacturer’s standards. PEX piping shall not be used for any application that would result in noncompliance with any provisions of the California Building Standards Code. 605.9.2 Mechanical Joints. Mechanical joints shall be installed in accordance with the manufacturer’s instal lation instructions.

    605.9.3 Push Fit Fittings. Removable and nonremovable push fit fittings that employ a quick assembly push fit connector shall comply with ASSE 1061. 605.10 PEX-AL-PEX Plastic Tubing and Joints. PEXAL-PEX plastic pipe or tubing and fitting joining methods shall be installed in accordance with the manufacturer’s installation instructions and shall comply with Section 605.10.1 and Section 605.10.1.1.

    [BSC, DSA-SS, HCD 1 & HCD 2] PEX-AL-PEX is not adopted for use in potable water supply and distribution sys-

    tems.

  • CPC § 6.32. Medium relevance — show source text

    ** Stainless steel joints shall be welded, assembled with approved tubing fittings, brazed with a material having a melting point in excess of 1000°F (538°C), or assembled with press-connect fittings listed to CSA/ANSI LC 4/CSA 6.32. Brazing alloys and fluxes shall be recommended by the manufacturer for use on stainless steel alloys. [NFPA 54:5.5.7.3] 1308.4.7.4 Flared Joints. Flared joints shall be used only in systems constructed from nonferrous pipe and tubing where experience or tests have demonstrated that the joint is suitable for the conditions and where provisions are made in the design to prevent separation of the joints. [NFPA 54:5.5.7.4] 1308.4.7.5 Metallic Pipe Fittings. Metallic fittings shall comply with the following:

    (1) Threaded fittings in sizes exceeding 4 inches (100 mm) shall not be used. (2) Fittings used with steel, stainless steel, or wrought-iron pipe shall be steel, stainless steel, copper alloy, malleable iron, or castiron. (3) Fittings used with copper or copper alloy pipe shall be copper or copper alloy. (4) Fittings used with aluminum alloy pipe shall be aluminum alloy. (5) Cast-iron fittings shall comply with the following: (a) Flanges shall be permitted.

    (b) Bushings shall not be used.

    (c) Fittings shall not be used in systems containing flammable gas-air mixtures.

    (d) Fittings in sizes 4 inches (100 mm) and larger shall not be used indoors unless

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    1308.4.8.3 Compression-Type Mechanical Joints. Where compression-type mechanical joints are used, the gasket material in the fitting shall be compatible with the plastic piping and with the gas distributed by the system. An internal tubular rigid stiffener shall be used in conjunction with the fitting. The stiffener shall be flush with the end of the pipe or tubing and shall extend at least to the outside end of the compression fitting when installed. The stiffener shall be free of rough or sharp edges and shall not be a force fit in the plastic. Split tubular stiffeners shall not be used. [NFPA 54:5.5.8(3)] 1308.4.8.4 Liquefied Petroleum Gas Piping Systems. Plastic piping joints and fittings for use in LP-Gas piping systems shall be in accordance with NFPA 58. [NFPA 54:5.5.8(4)] 1308.4.9 Flange Specifications. Cast iron flanges shall be in accordance with ASME B16.1. [NFPA 54:5.5.9.1.1] 1308.4.9.1 Steel Flanges. Steel flanges shall be in accordance with the following:

    (1) ASME B16.5 or

  • CPC § 705.8.1 Medium relevance — show source text

    705.8.1 Mechanical Joints. Mechanical joints shall be designed to provide a permanent seal and shall be of the mechanical or push-on joint type. The push-on joint shall include an elastomeric gasket that complies with ASTM C425 and shall provide a compressive force against the spigot and socket after assembly to provide a permanent seal. 705.9 Special Joints. Special joints shall comply with Section 705.9.1 through Section 705.9.4. 705.9.1 Slip Joints. In fixture drains and traps, slip joints of approved materials shall be permitted to be used in accordance with their approvals. 705.9.2 Expansion Joints. Expansion joints shall be accessible, except where in vent piping or drainage stacks, and shall be permitted to be used where necessary to provide for expansion and contraction of the pipes.

    705.9.3 Ground Joint, Flared, or Ferrule Con- nections. Copper or copper alloy ground joint flared, or ferrule-type connections that allow adjustment of tubing, but provide a rigid joint where made up, shall not be considered as slip joints.

    705.9.4 Transition Joint. A solvent cement transition joint between ABS and PVC building drain and building sewer shall be made using listed transition solvent cement in accordance with ASTM D3138.

    [HCD 1 & HCD 2] Plastic pipe and fittings joined with solvent cement shall utilize Low VOC primer(s), if a primer is required, and Low VOC cement(s) as defined in Section 214.0.

    705.10 Joints Between Various Materials. Joints

    between various materials shall be installed in accordance

    with the manufacturer’s installation instructions and with Section 705.10.1 through Section 705.10.4. Mechanical couplings used to join different materials shall comply with ASTM C1173 for belowground use, ASTM C1460 for aboveground use, or ASTM C1461 for aboveground and belowground use. 705.10.1 Copper or Copper Alloy Pipe to Cast- Iron Pipe. Joints from copper or copper alloy pipe or tubing to cast-iron pipe shall be made with a listed compression-type joint or copper alloy ferrule. The copper or copper alloy pipe or tubing shall be soldered or brazed to the ferrule, and the ferrule shall be joined to the castiron hub by a compression or caulked joint.

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    SANITARY DRAINAGE

    705.10.2 Copper or Copper Alloy Pipe to Threaded Pipe Joints. Joints from copper or copper alloy pipe or tubing to threaded pipe shall be made by the use of a listed copper alloy adapter or dielectric fitting. The joint between the copper or copper alloy pipe and the fitting shall be a soldered or brazed, and the connection between the threaded and the fittings shall be made with a standard pipe size threaded joint. 705.10.3 Plastic Pipe to Other Materials. Where connecting plastic pipe to other types of plastic or other types of piping material; approved listed adapter or transition fittings and listed for the specific transition intended shall be used. Except as provided in Section 705.9.4, PVC and ABS pipe and fittings shall not be solvent welded to any other unlike material. **705.10.4 Stainless Steel Pipe to Other Materials.

  • CPC § 1323.5.1 Medium relevance — show source text

    1323.5.1, 1323.5.4, 1323.5.5,

    1504.7.2, H 601.2

    BACKFLOW

    Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204.0

    Prevention . . . . . . . . . . . . . . . . . . . . . . . . . 602.2, 602.3

    Prevention devices

    or assembly . . . . . . . . . . . . 603.1, Table 603.2, 603.3

    BACKFLOW CONNECTION . . . . . . . . . . . . . . .204.0, 603.0

    BACKFLOW PREVENTERS

    Approved standards . . . . . . . . . . . . . . . . . . .Table 603.2

    Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .204.0

    For hot water . . . . . . . . . . . . . . . . . . . . . . . . . . .603.4.5

    Integral . . . . . . . . . . . . . . . . . . . . . . . . . . . .417.2, 417.3,

    417.4, 603.4.6

    Prohibited locations . . . . . . . . . . . . . . . . . . . . . .603.4.9

    Protection from damage . . . . . . . . . . . . . . . . . . .E 302.6 Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .603.2 BACKFLOW PREVENTION . . . . . . . . . . . . . . .602.3, 603.3

    BACK-TO-BACK FIXTURES . . . . . . . . . . . . . . . . . . . .704.2

    BACKWATER VALVES

    Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204.0

    Where Required. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 710.6 BALLCOCKS . . . . . . . . . . . . . . . . . . . .Table 603.2, 603.5.2

    BAPTISTRIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .406.1

    BATHROOM, HALF, DEFINITION . . . . . . . . . . . . . . . .204.0

    BATHROOM GROUP . . . . . . . . . . . . .204.0, 908.2, C 303.0

    BATHTUB, PROHIBITED TYPE . . . . . . . . . . . . . . . . .405.3

    BATHTUBS AND

  • CPC § 0.2 Medium relevance — show source text

    Surfaces to be joined shall be cleaned bright by manual or mechanical means. Flux shall be applied to pipe or tubing and fittings and shall conform to ASTM B813, and shall become noncorrosive and nontoxic after soldering. Insert pipe or tubing

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    WATER SUPPLY AND DISTRIBUTION

    into the base of the fitting and remove excess flux. Pipe or tubing and fitting shall be supported to ensure a uniform capillary space around the joint. Heat shall be applied using an air or fuel torch with the flame perpendicular to the pipe or tubing using acetylene or an LP gas. Preheating shall depend on the size of the joint. The flame shall be moved to the fitting cup and alternate between the pipe or tubing and fitting. Solder conforming to ASTM B32 shall be applied to the joint surfaces until capillary action draws the molten solder into the cup. Solder and fluxes with a lead content that exceeds 0.2 percent shall be prohibited in piping systems conveying potable water. Joint surfaces shall not be disturbed until cool and any remaining flux residue shall be cleaned. 605.1.5 Threaded Joints. Threaded joints for copper or copper alloy pipe shall be made with pipe threads that comply with ASME B1.20.1. Thread sealant tape or compound shall be applied only on male threads, and such material shall be of approved types, insoluble in water, and nontoxic.

    605.2 CPVC Plastic Pipe and Joints. CPVC plastic pipe and fitting joining methods shall be installed in accordance with the manufacturer’s installation instructions and shall comply with Section 605.2.1 through Section 605.2.3. 605.2.1 Mechanical Joints. Mechanical joints shall include compression, flanged, grooved and push fit fittings. 605.2.1.1 Push Fit Fittings. Removable and nonremovable push fit fittings that employ a quick assembly push fit connector shall comply with ASSE 1061.

    605.2.2 Solvent Cement Joints. Solvent cement joints for CPVC pipe and fittings shall be clean from dirt and moisture. Solvent cements shall comply with ASTM F493, requiring the use of a primer shall be orange in color. The primer shall be colored and shall comply with ASTM F656. Listed solvent cement that complies with ASTM F493 and that does not require the use of primers, yellow, green, or red in color, shall be permitted for pipe and fittings that comply with ASTM D2846, [1] ⁄ 2 of an inch (15 mm) through 2 inches (50 mm) in diameter or ASTM F442, [1] ⁄ 2 of an inch (15 mm) through 3 inches (80 mm) in diameter. Apply primer where required inside the fitting and to the depth of the fitting on pipe. Apply liberal coat of cement to the outside surface of pipe to depth of fitting and inside of fitting. Place pipe inside fitting to forcefully bottom the pipe in the socket and hold together until joint is set.

Frequently asked questions

Why does the CPC ban push‑fit and compression fittings for medical gas?

Because medical gas and vacuum systems require permanent joints with mechanical, thermal and sealing integrity equivalent to brazed joints; the code explicitly prohibits quick‑assembly push‑fit, flared, compression and straight‑threaded unions in the distribution system to avoid leaks and accidental disassembly. § 1322.7 and § 1322.6.

Are unions always prohibited?

Straight‑threaded unions and other straight‑threaded connections are prohibited in the medical gas distribution system per § 1322.7 (2). A dielectric union is conditionally permitted only where required by the equipment manufacturer and meeting § 1322.6.1.

Can I use push‑fit fittings on the alarm tubing or gauge connections?

No — § 1322.7 prohibits push‑fit fittings throughout medical gas and vacuum distribution systems, which includes alarm device connections and associated tubing. For limited threaded uses (indicators, alarm devices and source‑side equipment) follow § 1322.5.

What joining method should I specify instead of compression or push‑fit?

Specify brazed joints or listed/approved metallic gas tube fittings that provide permanent, brazed‑equivalent integrity per § 1322.6, or approved memory‑metal or axially swaged fittings where the chapter permits them.

Are the prohibitions the same for non‑medical plumbing in the same building?

No. Push‑fit and compression fittings are commonly allowed in potable water and other non‑medical plumbing per water chapters (e.g., § 605.1.3.3, § 605.9.3). Medical gas distribution is a special case and the medical gas chapter overrides those general allowances — see § 1322.7.

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California Plumbing Code