CPC · California Plumbing Code

What minimum gas volume and outlet sizes are required for appliances?

The CPC requires that each gas piping outlet be sized to deliver at least the appliance manufacturer’s stated maximum hourly demand, and outlet connections must be no smaller than 1/2 inch (15 mm) for normal appliances and 3/4 inch (20 mm) for mobile homes; gas-specific gravity assumptions (0.60 for natural gas, 1.50 for LPG) must be used or corrected with supplier data.

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Last reviewed: July 6, 2026

What the code requires — plain English

  • The required gas volume at each piping outlet must be at least the appliance manufacturer’s maximum hourly rating. See § 1214.2 .
  • Pipe sizing and tables in this chapter are based on a gas specific gravity of 0.60 for natural gas and 1.50 for undiluted LPG; use your gas supplier’s conversion factors when different gases are used. See § 1214.1 .
  • The supply piping outlet size must be no smaller than 1/2 inch (15 mm); for mobile homes the minimum is 3/4 inch (20 mm). See § 1214.4 .

The single most important rule: size the gas outlet to supply at least the appliance manufacturer’s stated maximum hourly requirement, and never provide an outlet smaller than 1/2" (3/4" for mobile homes). See § 1214.2 and § 1214.4 .

Requirements in detail

1) Minimum gas volume at an outlet

  • What to use: Take the hourly gas volume required at each outlet as not less than the appliance manufacturer’s maximum hourly rating (i.e., use the appliance’s stated maximum input as the outlet demand). § 1214.2 .
  • Why this matters: The code requires actual appliance ratings rather than assumptions so the piping can be sized to deliver adequate gas under maximum load. § 1214.2 .

2) Basis for pipe-sizing tables (gas properties)

  • Sizing tables in this chapter assume a gas specific gravity of 0.60 (natural gas) and 1.50 (undiluted LPG). If the gas has a different specific gravity, the serving gas supplier’s conversion factors must be used when applying the tables. § 1214.1 .

3) Minimum piping outlet sizes

  • Minimum outlet diameter (general appliances): 1/2 inch (15 mm). § 1214.4 .
  • Minimum outlet diameter (mobile homes): 3/4 inch (20 mm). § 1214.4 .

Quick reference table (decision-relevant values)

Decision item Value / Threshold Code Reference
Minimum hourly gas volume at an outlet Not less than the appliance manufacturer’s maximum hourly rating § 1214.2
Gas specific gravity assumption (natural gas) 0.60 (use supplier conversion if different) § 1214.1
Gas specific gravity assumption (undiluted LPG) 1.50 (use supplier conversion if different) § 1214.1
Minimum piping outlet (general appliances) 1/2 in. (15 mm) § 1214.4
Minimum piping outlet (mobile homes) 3/4 in. (20 mm) § 1214.4

Exceptions & special cases

  • The code ties sizing to the manufacturer’s maximum hourly rating; if the appliance is unspecified at design time, supplementary guidance (such as typical-appliance tables) may be used as a reference — see related provisions (e.g., § 1214.3) for estimating loads. Use the serving gas supplier’s conversion factors when gas properties differ from the table assumptions. § 1214.1, § 1214.2 .
  • Minimum outlet sizes are absolute minima; actual installed outlet size may need to be larger to meet flow requirements and pressure-drop limits when multiple appliances or long runs are involved (size from the appropriate piping tables in Chapter 1215 and the serving utility data). § 1214.4 .

Common mistakes

  • Assuming the code’s pipe-size tables alone guarantee compliance without first establishing the actual manufacturer’s maximum hourly rating for each appliance. The code requires the manufacturer rating be used as the required outlet volume. § 1214.2 .
  • Providing an outlet smaller than 1/2 in. for a standard appliance, or smaller than 3/4 in. for a mobile home — these are absolute minima in § 1214.4 .
  • Forgetting to adjust for a gas with nonstandard specific gravity; sizing tables assume 0.60 (natural gas) or 1.50 (LPG) and require conversion factors from the supplier when different. § 1214.1 .

Worked example — one concrete scenario

Scenario: You are installing a new gas range in a house (not a mobile home). The appliance manufacturer lists a maximum input of 40,000 Btu/hour.

Step 1 — Determine required outlet volume:

  • Per code, take the outlet hourly requirement as the appliance’s maximum hourly rating: 40,000 Btu/hr (this is the demand that the piping must be able to supply). § 1214.2 .

Step 2 — Confirm minimum outlet size:

  • The outlet must be at least 1/2 in. (15 mm). § 1214.4 .

Step 3 — If you must convert to cubic feet per hour (cfh) to use the piping tables:

  • Divide the appliance input (Btu/hr) by the average Btu per cubic foot of the site gas (obtain this number from the serving gas supplier). The code permits this conversion approach. (See related guidance in the code on converting inputs to gas volume.) § 1214.3 .
    Example conversion (illustrative only): if the gas is 1,000 Btu/ft³ (typical approximation; confirm with the supplier), 40,000 Btu/hr ÷ 1,000 Btu/ft³ = 40 cfh. Then use Chapter 1215 tables (with specific-gravity correction if needed) to select pipe size to carry that flow over the planned run length and fittings. Note: the code requires supplier conversion for nonstandard gas gravities. § 1214.1 .

Related provisions

  • § 1214.1 — Basis for gas-specific assumptions and conversion factors (specific gravities).
  • § 1214.2 — Hourly volume requirement at each outlet (manufacturer’s maximum).
  • § 1214.3 — Converting appliance input (Btu) to gas volume (cfh) and use of reference tables (useful when appliances aren’t specified).
  • § 1214.4 — Minimum outlet sizes (1/2" general, 3/4" mobile homes).
  • § 1215.0 — Required gas piping size and methods for selecting pipe sizes (use this with outlet demands).

Code references

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

  • CPC § 1214.1 High relevance — show source text

    1214.1 General. The following regulations shall comply with this section and Section 1215.0, shall be the standard for the installation of gas piping. Natural gas regulations and tables are based on the use of a gas having a specific gravity of 0.60 and for undiluted liquefied petroleum gas, having a specific gravity of 1.50. Where gas of a different specific gravity is to be delivered, the specific gravity conversion factors provided by the serving gas supplier shall be used in sizing piping systems from the pipe sizing tables in this chapter.

    1214.2 Volume. The hourly volume of gas required at each piping outlet shall be taken as not less than the maximum hourly rating as specified by the manufacturer of the appliance or appliances to be connected to each such outlet.

    1214.3 Gas Appliances. Where the gas appliances to be installed have not been specified, Table 1208.3.1 shall be permitted to be used as a reference to estimate requirements of typical appliances. To obtain the cubic feet per hour (m [3] /h) of gas required, divide the input of the appliances by the average Btu (kW•h) heating value per cubic foot (m [3] ) of the gas. The average Btu (kW•h) per cubic foot (m [3] ) of the gas in the area of the installation shall be permitted to be obtained from the serving gas supplier.

    1214.4 Size of Piping Outlets. The size of the supply piping outlet for a gas appliance shall be not less than [1] ⁄ 2 of an inch in diameter (15 mm).

    The size of a piping outlet for a mobile home shall be not less than [3] ⁄ 4 of an inch in diameter (20 mm).

    2025 CALIFORNIA PLUMBING CODE 233

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    FUEL GAS PIPING

    1215.0 Required Gas Piping Size. 1215.1 Pipe Sizing Methods. Where the pipe size is to be determined using any of the methods in Section 1215.1.1 through Section 1215.1.3, the diameter of each pipe segment shall be obtained from the pipe sizing tables in Section 1215.2 or from the sizing equations in Section 1215.3. [NFPA 54:6.1]

    1215.1.1 Longest Length Method. The pipe size of each section of gas piping shall be determined using the longest length of piping from the point of delivery to the most remote outlet and the load of the section. [NFPA 54:6.1.1] (see calculation example in Figure 1215.1.1)

    1215.1.2 Branch Length Method. Pipe shall be sized as follows:

    (1) Pipe size of each section of the longest pipe run from the point of delivery to the most remote outlet shall be determined using the longest run of piping and the load of the section.

    (2) The pipe size of each section of branch piping not previously sized shall be determined using the length of piping from the point of delivery to the most remote outlet in each branch and the load of the section. [NFPA 54:6.1.2]

  • California Plumbing Code Medium relevance — show source text

    200|66 600|44 400|33 300|26 650|22 200| |15|2473|238 000|119 000|79 333|59 500|47 600|39 650|

    SIZE OF PIPE FLOW
    (1⁄4 inch per foot
    slope)    		 MAXIMUM ALLOWABLE HORIZONTAL PROJECTED ROOF AREAS AT VARIOUS RAINFALL RATES
    (square feet)    		 Col4 Col5 Col6 Col7 Col8
    inches gpm 1 (in/h) 2 (in/h) 3 (in/h) 4 (in/h) 5 (in/h) 6 (in/h)
    3 48 4640 2320 1546 1160 928 773
    4 110 10 600 5300 3533 2650 2120 1766
    5 196 18 880 9440 6293 4720 3776 3146
    6 314 30 200 15 100 10 066 7550 6040 5033
    8 677 65 200 32 600 21 733 16 300 13 040 10 866
    10 1214 116 800 58 400 38 950 29 200 23 350 19 450
    12 1953 188 000 94 000 62 600 47 000 37 600 31 350
    15 3491 336 000 168 000 112 000 84 000 67 250 56 000
    SIZE OF PIPE FLOW
    (1⁄2 inch per foot
    slope)    		 MAXIMUM ALLOWABLE HORIZONTAL PROJECTED ROOF AREAS AT VARIOUS RAINFALL RATES
    (square feet)    		 Col4 Col5 Col6 Col7 Col8
    inches gpm 1 (in/h) 2 (in/h) 3 (in/h) 4 (in/h) 5 (in/h) 6 (in/h)
    3 68 6576 3288 2192 1644 1310 1096
    4 156 15 040 7520 5010 3760 3010 2500
    5 278 26 720 13 360 8900 6680 5320 4450
    6 445 42 800 21 400 14 267 10 700 8580 7140
    8 956 92 000 46 000 30 650 23 000 18 400 15 320
    10 1721 165 600 82 800 55 200 41 400 33 150 27 600
    12 2768 266 400 133 200 88 800 66 600 53 200 44 400
    15 4946 476 000 238 000 158 700 119 000 95 200 79 300
  • CPC § 11.0 Medium relevance — show source text

    11.0 - 1.11.11_|||X|||||||||||||||||||||| |1.13.0||||||||||||||||||||X||||| |Division II - Scope and
    Administration||||||||||||||||||||||||| |101.0||||||||||X|X|X||X|X|||||||||| |102.0||||||||||X|X|X||X|X|||||||||| |103.0||||||||||X|X|X||X|X|||||||||| |104.2 Items 1 & 2||||X|X|||||||||||||||||||| |104.3.1||||||||||X|X|X||X|X|||||||||| |104.4.3.1|X|||||||||||||||||||||||| |105.0||||||||||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.

    2 2025 CALIFORNIA PLUMBING CODE

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    CHAPTER 1

    ADMINISTRATION

    DIVISION I

    CALIFORNIA ADMINISTRATION

    1.1.0 General.

    1.1.1 Title. These regulations shall be known as the Califor- nia Plumbing Code, may be cited as such and will be referred to herein as “this code.” The California Plumbing Code is Part 5 of thirteen parts of the official compilation and publi- cation of the adoption, amendment, and repeal of plumbing regulations to the California Code of Regulations, Title 24, also referred to as the California Building Standards Code. This part incorporates by adoption the 2024 Uniform Plumb- ing Code of the International Association of Plumbing and Mechanical Officials with necessary California amendments.

    1.1.2 Purpose. The purpose of this code is to establish the minimum requirements to safeguard the public health, safety and general welfare through structural strength, means of egress facilities, stability, access to persons with disabilities, sanitation, adequate lighting and ventilation, and energy con- servation; safety to life and property from fire and other haz- ards attributed to the built environment; and to provide safety to fire fighters and emergency responders during emergency operations.

    1.1.3 Scope. The provisions of this code shall apply to the construction, alteration, movement, enlargement, replace- ment, repair, equipment, use and occupancy, location, main- tenance, removal, and demolition of every building or structure or any appurtenances connected or attached to such buildings or structures throughout the State of California.

  • CPC § 31-2022 Medium relevance — show source text

    2025 CALIFORNIA PLUMBING CODE 453

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

    454 2025 CALIFORNIA PLUMBING CODE

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

    "The information contained in this appendix is not part of this American National Standard (ANS) and has not been processed in accordance with ANSI's requirements for an ANS. As such, this appendix may contain material that has not been subjected to public review or a consensus process. In addition, it does not contain requirements necessary for conformance to the standard."

    The following IAPMO Installation Standard is included here for the convenience of the users of the Uniform Plumbing Code. It is not considered as a part of the Uniform Plumbing Code unless formally adopted as such. This Installation Standard is an independent, stand-alone document published by the International Association of Plumbing and Mechanical Officials and is printed herein by the expressed written permission of IAPMO.

    INSTALLATION STANDARD FOR PEX TUBING SYSTEMS

    FOR HOT- AND COLD-WATER DISTRIBUTION

    IAPMO IS 31-2022

    The provisions contained in this appendix are not mandatory unless specifically adopted by a state agency, or referenced in the adopting ordinance.

    1 Scope

    1.1 General

    1.1.1 This Standard specifies requirements for the installation of SDR 9 CTS crosslinked polyethylene (PEX) tubing and fittings, including cold-expansion, crimp, press, and mechanical compression fittings, intended for hot- and cold-water distribution systems within buildings.

    1.1.2 This Standards applies to

    (a) SDR 9 CTS PEX tubing complying with ASTM F876 and pressure-rated in accordance with PPI TR-3; and (b) PEX fitting systems complying with (i) ASTM F877, for mechanical compression fittings and metal or plastic insert fittings with stainless steel press sleeves; (ii) ASTM F1807 or ASTM F2159, for metal or plastic insert fittings with copper crimp rings; (iii) ASTM F1960, for cold expansion fittings with PEX reinforced rings; or (iv) ASTM F2080, for cold expansion fittings with metal compression sleeves. 1.2 Terminology

    In this Standard,

    (a) “shall” is used to express a requirement, i.e., a provision that the user is obliged to satisfy to comply with the Standard; (b) “should” is used to express a recommendation, but not a requirement; (c) “may” is used to express an option or something permissible within the scope of the Standard; and (d) “can” is used to express a possibility or a capability. Notes accompanying sections of the Standard do not specify requirements or alternative requirements; their purpose is to separate explanatory or informa

    tive material from the text. Notes to tables and figures are considered part of the table or figure and can be written as requirements.

    1.3 Units of Measurement

    SI units are the primary units of record in global commerce. In this Standard, the inch/pound units are shown in parentheses. The values stated in each measurement system are equivalent in application, but each unit system is to be used independently. All references to gallons are to U.S. gallons.

    2 Reference Publications

  • CPC § 1323.13.3 Medium relevance — show source text

    2, 1323.13.3| |1326.4 - 1326.10|1326.5 - 1326.11| |1505.6 - 1505.14|1505.5 - 1505.13| |Figure 1505.10|Figure 1505.9| |1506.6 - 1506.13|1506.5 - 1506.12| |1603.3 - 1603.4|1603.4 - 1603.5| |Table 1603.4|Table 1603.5| |1603.5 - 1603.19|1603.6 - 1603.20| |1603.20|1503.2.4| |L 402.9 - L 402.11|L 402.8 - L 402.10| |L 404.9 - L 404.12|L 404.8 - L 404.11| |L 411.5, L 411.6|L 411.2, L411.3| |L 411.7|L 411.4| |L 411.9 - L 411.12|L 411.5 - L 411.8|

    xxii 2025 CALIFORNIA PLUMBING CODE

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    RELATED PUBLICATIONS AND SERVICES

    The Documents Listed are Not by this Reference Adopted by The State of California.

    IAPMO provides a variety of other products which are useful for inspectors, building officials, architects, engineers,

    manufacturers, contractors, plumbers, and apprentices.

    IAPMO Headquarters Directory

    4755 East Philadelphia Street, Ontario, California 91761-2816

    Publication Order Desk Phone: 800-85-IAPMO

    Publication Toll Free Fax: 877-85-CODES

    E-mail: iapmo@iapmo.org

    Website: www.iapmo.org

    Free Code Question: 800-201-0335

    Uniform Plumbing Code – 2024 Edition:

    The Uniform Plumbing Code is the most widely adopted plumbing code in the world. The 2024 edition contains complete “turnkey” requirements for the installation and maintenance of plumbing systems, all in one easy to use book.

    Uniform Plumbing Code Illustrated Training Manual:

    The UPC Illustrated Training Manual is an excellent reference for anyone involved in the plumbing industry. It contains an extensive definitions section and several hundred comprehensive technical diagrams and illustrations. It serves as a textbook, and it also is useful as a valuable tool for explaining the intent and use of the Code.

    Uniform Plumbing Code Study Guide:

    This book is the perfect complement to the UPC Illustrated Training Manual. Alone, it constitutes a complete self-study course for learning the UPC. It has hundreds of questions, general practice exams, and plumbing math, pipe sizing exercises and fitting identification. A big help in getting you ready for a certification exam!

    Guide to Important Code Questions to the Uniform Plumbing Code:

    An excellent reference for learning and understanding plumbing code changes and identifies code changes between editions. It is a useful tool for preparing code change proposals.

    Uniform Mechanical Code – 2024 Edition:

    The Uniform Mechanical Code contains complete requirements for the installation and maintenance of heating, ventilating, cooking and refrigeration systems.

    Uniform Mechanical Code Illustrated Training Manual:

    Contains technical diagrams and illustrations that demonstrate the intent and use of the UMC. A great reference for everyone involved in Mechanical HVACR design and installation.

    Uniform Mechanical Code Study Guide:

  • CPC § 705.10 Medium relevance — show source text

    Waste,
    and Vent (DWV), Sewer, Sanitary, and Storm Plumbing Sys-
    tems for Above and Below Ground Use|Joints|705.10|

    340 2025 CALIFORNIA PLUMBING CODE

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    REFERENCED STANDARDS

    TABLE 1701.1 (continued) REFERENCED STANDARDS

    STANDARD NUMBER STANDARD TITLE APPLICATION REFERENCED
    SECTION
    ASTM C1540-2020 Standard Specification for Heavy-Duty Shielded Couplings
    Joining Hubless Cast Iron Soil Pipe and Fittings    		 Joints 705.2.2
    ASTM C1563-2008
    (R2021)    		 Standard Test Method for Gaskets for Use in Connection with
    Hub and Spigot Cast Iron Soil Pipe and Fittings for Sanitary
    Drain, Waste, Vent, and Storm Piping Applications    		 Joints 705.2.2
    ASTM C1822-2021 Standard Specification for Insulating Covers on Accessible
    Lavatory Piping    		 Miscellaneous 403.3
    ASTM D1253-2014 Standard Test Method for Residual Chlorine in Water Miscellaneous 1506.10.6, 1603.4.1
    ASTM D1785-2021a Standard Specification for Poly (Vinyl Chloride) (PVC) Plastic
    Pipe, Schedules 40, 80, and 120    		 Piping Table 604.1, Table
    701.2
    ASTM D2235-2021 Standard Specification for Solvent Cement for Acrylonitrile-
    Butadiene-Styrene (ABS) Plastic Pipe and Fittings    		 Joints 705.1.2
    ASTM D2239-2021 Standard Specification for Polyethylene (PE) Plastic Pipe
    (SIDR-PR) Based on Controlled Inside Diameter    		 Piping Table 604.1
    ASTM D2241-2020 Standard Specification for Poly (Vinyl Chloride) (PVC) Pressure-
    Rated Pipe (SDR Series)    		 Piping Table 604.1
    ASTM D2464-2015 Standard Specification for Threaded Poly (Vinyl Chloride)
    (PVC) Plastic Pipe Fittings, Schedule 80    		 Fittings Table 604.1
    ASTM D2466-2021 Standard Specification for Poly (Vinyl Chloride) (PVC) Plastic
    Pipe Fittings, Schedule 40    		 Fittings Table 604.1
    ASTM D2467-2020 Standard Specification for Poly (Vinyl Chloride) (PVC) Plastic
    Pipe Fittings, Schedule 80    		 Fittings Table 604.1
    ASTM D2513-2020 Standard Specification for Polyethylene (PE) Gas Pressure
    Pipe, Tubing, and Fittings    		 Piping 1208.5.4, 1208.5.6.2,
    1208.5.10.2,
    1210.1.7.1(1)
    ASTM D2564-2020 Standard Specification for Solvent Cements for Poly (Vinyl
    Chloride) (PVC) Plastic Piping Systems    		 Joints 605.12.2, 705.6.
  • California Plumbing Code Medium relevance — show source text


    5
    10
    15
    20|NA
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    NA|38
    35
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    67
    59
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    115
    105
    95
    80|NA
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    183
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    156
    144|163
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    252
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    202| |30|2
    5
    10
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    20
    30|NA
    NA
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    NA|41
    NA
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    NA|81
    75
    66
    NA
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    105
    88
    NA|NA
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    196
    182
    168
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    279
    260
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    182| |50|2
    5
    10
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    30|NA
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    NA|160
    149
    136
    124
    NA
    NA|NA
    NA
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    NA|NA
    NA
    NA
    NA
    NA
    NA|250
    228
    212
    195
    180
    NA|NA
    NA
    NA
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    NA
    NA|NA
    NA
    NA
    NA
    NA
    NA|350
    321
    301
    278
    258
    NA| |Minimum
    internal area of
    chimney
    (square inches)|Minimum
    internal

  • CPC § 309.0 Medium relevance — show source text

    2025 CALIFORNIA PLUMBING CODE 469

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    IS 33

    Uniform Plumbing Code References for Ductile Iron and PVC Pressure Building Supply and Exterior Cold-Water Piping

    The following sections of the 2024 Uniform Plumbing Code apply to ductile iron and PVC pressure building supply and exterior cold-water piping.

    Chapter 3 General Regulations

    309.0 Workmanship

    312.0 Protection of Piping, Materials, and Struc tures

    313.0 Hangers, Supports, and Anchors

    314.0 Trenching, Excavation, and Backfill

    Chapter 6 Water Supply and Distribution

    604.0 Materials (water piping)

    Table 604.1 Materials for Building Supply and Water Distribution Piping and Fittings

    605.4 Ductile Iron Pipe and Joints

    605.12 PVC Plastic Pipe and Joints

    605.16.2 Plastic Pipe to Other Materials

    609.0 Installation, Testing, Unions, and Location

    Abbreviations

    IAPMO International Association of Plumbing and Mechanical Officials

    UPC Uniform Plumbing Code published by IAPMO

    AWWA American Water Works Association

    CSA Canadian Standards Association

    Applicable Standards.

    ASME B16.4 Gray Iron Threaded Fittings Classes 125 and 250

    ASTM D1785 Poly (Vinyl Chloride) (PVC) Plastic Pipe, Schedules 40, 80, and 120

    ASTM D2241 Poly (Vinyl Chloride) (PVC) Pressure-Rated Pipe (SDR Series)

    ASTM D2466 Poly (Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 40

    ASTM D2467 Poly (Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 80

    ASTM F1970 Special Engineered Fittings, Appurtenances or Valves for use in Poly (Vinyl Chloride) (PVC) or Chlorinated Poly (Vinyl Chloride) (CPVC) Systems

    AWWA C110 Ductile Iron and Gray-Iron Fittings

    AWWA C111 Rubber-Gasket Joints for Ductile-Iron Pressure Pipe and Fittings

    AWWA C151 Ductile-Iron Pipe, Centrifugally Cast

    AWWA C153 Ductile-Iron Compact Fitting

    AWWA C900 Polyvinyl Chloride (PVC) Pressure Pipe and Fabricated Fittings, 4 in. through 12 in. (100 mm through 300 mm)

    AWWA C904 Crosslinked Polyethylene (PEX) Pressure Tubing, ½ in. through 3 In. (13 mm through 76 mm), for Water Service

    AWWA C907 Injection-Molded Polyvinyl Chloride (PVC) Pressure Fittings, 4 In, through 12 in (100 mm through 300 mm) for Water, Wastewater and Reclaimed Water Service

    IAPMO/

    ANSI UPC-1 Uniform Plumbing Code

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  • CPC § 312.0 Medium relevance — show source text

    312.0 Protection of Piping, Materials, and Structures

    314.0 Trenching, Excavation, and Backfill

    701.3 Drainage Fittings

    705.5.1.1 Butt Fusion Joints

    705.5.1.2 Electro-Fusion Joints

    705.5.1.3 Socket-Fusion Joints

    723.0 Building Sewer Test

    TABLE 1

    CLEANOUTS (See Section 4.6.1)

    The following standards from Tables 1701.1 and 1701.2 of the 2024 Uniform Plumbing Code apply.

    Table 1701.1 Standards

    ASTM D2239 Polyethylene (PE) Plastic Pipe (SIDRPR) Based on Controlled Inside Diameter

    ASTM D2683 Socket-Type Polyethylene Fittings for Outside Diameter-Controlled Polyethylene Pipe and Tubing

    ASTM D3261 Butt Heat Fusion Polyethylene (PE) Plastic Fittings for Polyethylene (PE) Plastic Pipe and Tubing

    ASTM F714 Polyethylene (PE) Plastic Pipe (DRPR) Based on Outside Diameter

    ASTM F894 Polyethylene (PE) Large Diameter Profile Wall Sewer and Drain Pipe

    ASTM F1055 Electrofusion Type Polyethylene Fittings for Outside Diameter Controlled Polyethylene and Crosslinked Polyethylene (PEX) Pipe and Tubing

    ASTM F2620 Heat Fusion Joining of Polyethylene Pipe and Fittings

    Table 1701.2 Standards

    ASTM D2657 Heat Fusion Joining of Polyolefin Pipe and Fittings

    IAPMO PS 25 Metallic Fittings for Joining Polyethylene Pipe for Water Service and Yard Piping

    Note: For SI units: 1 inch = 25 mm

    2025 CALIFORNIA PLUMBING CODE 453

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

    454 2025 CALIFORNIA PLUMBING CODE

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

    "The information contained in this appendix is not part of this American National Standard (ANS) and has not been processed in accordance with ANSI's requirements for an ANS. As such, this appendix may contain material that has not been subjected to public review or a consensus process. In addition, it does not contain requirements necessary for conformance to the standard."

    The following IAPMO Installation Standard is included here for the convenience of the users of the Uniform Plumbing Code. It is not considered as a part of the Uniform Plumbing Code unless formally adopted as such. This Installation Standard is an independent, stand-alone document published by the International Association of Plumbing and Mechanical Officials and is printed herein by the expressed written permission of IAPMO.

    INSTALLATION STANDARD FOR PEX TUBING SYSTEMS

    FOR HOT- AND COLD-WATER DISTRIBUTION

    IAPMO IS 31-2022

    The provisions contained in this appendix are not mandatory unless specifically adopted by a state agency, or referenced in the adopting ordinance.

    1 Scope

    1.1 General

    1.1.1 This Standard specifies requirements for the installation of SDR 9 CTS crosslinked polyethylene (PEX) tubing and fittings, including cold-expansion, crimp, press, and mechanical compression fittings, intended for hot- and cold-water distribution systems within buildings.

    1.1.2 This Standards applies to

  • CPC § 101.2.2 Medium relevance — show source text

    CFC—25: California Fire Code

    101.2.2, 101.4.2, 301.3.1, 302.2, 307.1, 308.1, 802.2.1, 802.2.3, 803.2.3, 803.4.1.1, 803.4.1.2, 803.4.1.3, 803.4.1.4, 803.4.1.5, 803.4.1.6, Table 804.5.1.1(1), 904.1.5, 1011.6.1.1, 1303.1.2, 1305.2.8.1, 1305.2.14, 1305.2.14.1, 1401.2, 1501.1, 1501.5, 1502.1, 1502.1.1, 1502.2, 1502.3, 1504.1, 1507.1, 1507.2

    CMC—25: California Mechanical Code

    302.2, 702.7, 807.1, 902.1.1, 1008.1, 1305.2.7.1, 1305.2.8, 1305.2.8.1

    CPC—25: California Plumbing Code

    302.2, 408.1, 702.7, 1009.1, 1009.2, 1009.3, 1009.5, 1302.1.6, 1503.1

    16-4 2025 CALIFORNIA EXISTING BUILDING CODE

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

    REFERENCED STANDARDS

    CRC—25: California Residential Code

    101.2, 101.4.1, 104.3.1, 109.3.3, 109.3.10, 302.2, 307.1, 308.1, 401.3, 402.1, 405.2.6, 502.2, 502.3, 502.4, 503.2, 503.3, 503.11, 505.2, 505.3, 507.3, 701.3, 702.4, 702.5, 706.2, 708.1, 805.2, 806.4, 809.1, 906.2, 907.1, 1011.2.1, 1103.1, 1103.2, 1103.3, 1104.1, 1201.4, 1302.1.2, 1302.1.3, 1302.1.3, 1303.1.3, 1401.2, 1402.1, 1402.2, 1402.2.1, 1402.3, 1402.4, 1402.5, 1402.6

    ICC 300—2023: ICC Standard on Bleachers, Folding and Telescopic Seating and Grandstands

    301.1.1, 401.1.1, 1401.1.1

    ICC A117.1—2017: Accessible and Usable Buildings and Facilities

  • CPC § 31-2022 Medium relevance — show source text

    Agency|BSC|BSC-
    CG|SFM|1|2|1-AC|AC|** SS**|SS/CC|1|1R|2|3|4|5|6|6|6|6|6|6|6|6|6| |Adopt Entire Chapter||||||||||X|X|X|X|X|X|X||||||||| |Adopt Entire Chapter as
    amended (amended
    sections listed below)||||||||||||||||||||||||| |Adopt only those sections
    that are listed below|X|||X|X|||X||||||||||||||||| |Chapter/Section||||||||||||||||||||||||| |IAPMO IS 31-2022|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 447

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

    448 2025 CALIFORNIA PLUMBING CODE

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

    APPENDIX I

    INSTALLATION STANDARDS

    CONTENTS

    Page

    IAPMO IS 26-2019 [e4]

    Trenchless Insertion of Polyethylene (PE) Pipe for Sewer Laterals................................................................451

    IAPMO IS 31-2022

    Installation Standard for PEX Tubing Systems for Hot- and Cold Water Distribution......................................455

    IAPMO IS 33-2019 [e2]

    Thrust Blocking for Rubber Gasketed and Solvent Cement Joints ................................................................463

    TCNA Handbook-2022

    For Ceramic, Glass, and Stone Tile Installation .............................................................................................471

    2025 CALIFORNIA PLUMBING CODE 449

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

    450 2025 CALIFORNIA PLUMBING CODE

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

    "The information contained in this appendix is not part of this American National Standard (ANS) and has not been processed in accordance with ANSI's requirements for an ANS. As such, this appendix may contain material that has not been subjected to public review or a consensus process. In addition, it does not contain requirements necessary for conformance to the standard."

    The following IAPMO Installation Standard is included here for the convenience of the users of the Uniform Plumbing Code. It is not considered as a part of the Uniform Plumbing Code unless formally adopted as such. This Installation Standard is an independent, stand-alone document published by the International Association of Plumbing and Mechanical Officials and is printed herein by the expressed written permission of IAPMO.

    TRENCHLESS INSERTION OF

  • CPC § 102.3 Medium relevance — show source text

    1

    CEBC—25: California Existing Building Code

    102.3, 1011.5.2, 1103.1, 1104.18, 1105.5.2

    CMC—25: California Mechanical Code

    201.3, 308.3, 605.1, 605.2.1.1, 605.2.1.2, 605.2.1.3, 605.2.1.4, 605.2.1.5, 605.3, 605.4, 605.4.2.3, 605.4.2.5, 605.5.2, 605.7, 606.1, 606.2, 608.1, 608.3, 608.4, 608.5, 608.8, 608.9.1, 608.10, 608.17, 610.1.1, 903.2.11.4, 904.14, 907.3.1, 909.1, 909.10.2, 909.13.1, 910.4.7, 915.6.1, 1006.2.2.3, 1011.16, 1020.6.1, 1207.4.7, 1207.6.1, 1207.6.1.2.2, 1207.11.8, 2104.2.1, 2105.3, 2301.1, 2301.6, 2309.3.1.2, 2311.3.1, 2311.4.3, 2311.8.2, 2311.8.8, 2311.8.10, 2404.9, 2404.9.2, 2504.5, 2703.2.2, 2703.10.4, 2703.14, 2803.2, 2803.3, 3001.1, 3003.1, 3004.2, 3108.12.1, 3108.12.2, 3703.5, 3804.1.1.7, 3904.1, 3905.3, Table 5003.1.1(1), 5003.8.4.2, 5003.8.5.2, 5003.8.6.2, 5004.3.1, 5303.7.6, 5303.16.9, 5305.5, 5306.2.2, 5306.2.3, 5307.4.4, 5504.2.1.3, 5504.2.2.3, 5505.4.1.1, 5701.3, 5703.6.1, 5704.2.8.9, 5705.3.7.5.1, 5706.2, 5706.4.4, 6003.1.3, 6003.2.3.2, 6004.2.2.7, 6005.3.1, 6005.3.2, 6103.2.1.7

    CPC—25: California Plumbing Code

Frequently asked questions

What does "hourly volume" mean in § 1214.2?

It means the amount of gas the outlet must be able to supply over an hour and, per the code, you must use the appliance manufacturer’s maximum hourly rating as that value. § 1214.2

Can I use a 1/4‑inch outlet if the appliance demand is small?

No — the code sets an absolute minimum outlet size of 1/2 in. (15 mm) for appliances (and 3/4 in. (20 mm) for mobile homes). § 1214.4

My project will use propane blended with other gases. Do I need to adjust sizing?

Yes. The chapter’s tables assume specific gravities of 0.60 (natural gas) and 1.50 (undiluted LPG). If the gas mixture has a different specific gravity, use the serving gas supplier’s conversion factors when applying the tables. § 1214.1

If appliances are unspecified at design, how do I estimate demand?

The code allows use of typical-appliance reference tables as an estimate (see related provisions such as § 1214.3) but final sizing must be checked against actual manufacturer maximum hourly ratings once appliances are selected.

Do I size the outlet or the run to supply the appliance?

Both: the outlet must be at least the minimum diameter required by § 1214.4, and the piping run (pipe sizes along the system) must be selected to carry the outlet’s required hourly volume per the pipe-sizing methods in Chapter 1215. § 1214.4, § 1215.0

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