What are the requirements for valves, shutoffs and excess-flow valves?

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

• CMC § 5.9.2 High relevance — show source text

  (1) Check valves.

  (2) Three-way valves (of the type that completely closes one side before starting to open the other side).

  (3) Reverse flow indicators controlling positive shutoff valves.

  (4) Normally closed air-actuated positive shutoff pressure regulators. [NFPA 54:5.9.2] 1308.11 Low-Pressure Protection. A protective device shall be installed between the meter and the appliance or equipment if the operation of the appliance or equipment is such that it could produce a vacuum or a dangerous reduction in gas pressure at the meter. Such protective devices include, but are not limited to, mechanical, diaphragm-operated, or electrically operated low-pressure shutoff valves. [NFPA 54:5.10]

  1308.12 Shutoff Valves. Shutoff valves shall be selected in

  accordance with Table 1308.12. Shutoff valves of size 1 inch

  (25 mm) National Pipe Thread and smaller shall be listed and labeled. Where used outdoors, such use shall be in accordance with the manufacturer’s recommendation. [NFPA 54:5.11]

  «

  «

  282 2025 CALIFORNIA MECHANICAL CODE

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

  FUEL GAS PIPING

  Exceptions: (1) A regulator and vent limiting means combination listed as complying with CSA/ANSI Z21.80/CSA 6.22, shall not be required to be vented to the outdoors.

  (2) A listed gas appliance regulator factory equipped with a vent limiting device is not required to be vented to the outdoors.

  (2) Materials for vent piping shall be in accordance with Section 1308.4 through Section 1308.4.10.5. (3) The vent terminus shall be designed to prevent the entry of water, insects, and other foreign matter that could cause blockage. (4) Vent piping shall be installed to minimize static loads and bending moments placed on the regulators and gas pressure control devices.

  (5) Vents shall terminate not less than 3 feet (914 mm) from a possible source of ignition. (6) At locations where a vent termination could be submerged during floods or snow accumulations, an antiflood-type breather vent fitting shall be installed, or the vent terminal shall be located above the height of the expected floodwaters or snow.

  (7) Vent piping from pressure regulators and gas pressure controls shall not be connected to a common manifold that serves a bleed line from a diaphragm-type gas valve.

  [NFPA 54:5.14]

  1309.0 Excess Flow Valve.

  1309.1 General. Where automatic excess flow valves are installed, they shall be listed in accordance with ANSI Z21.93/CSA 6.30 and shall be sized and installed in accordance with the manufacturers’ instructions. [NFPA 54:5.12]

  1310.0 Gas Piping Installation. 1310.1 Piping Underground. Underground gas piping shall be installed with sufficient clearance from any other underground structure to avoid contact therewith, to allow maintenance, and to protect against damage from proximity to other structures. Underground plastic piping shall be installed with sufficient clearance or shall be insulated from any source of heat so as to prevent the heat from impairing the serviceability of the pipe.

• CMC § 93.3 High relevance — show source text

  A-93.3

  Publication Date: 10/20/2021 Effective Date: 01/01/2022 Rev. 9c

  Purpose and Scope

  This gas design standard (GDS) provides specifications and design information for selecting and installing polyethylene (PE) and steel excess flow valves (EFVs).

  1 General Information

  1.1. EFVs are manufactured in accordance with American Society for Testing and Materials (ASTM International) F2138, “Standard Specification for Excess Flow Valves for Natural Gas Service,” and ASTM F1802, “Standard Test Method for Performance Testing of Excess Flow Valves.”

  1.2. Only personnel qualified as described in GDS D-34, “Qualifications for Joining Polyethylene Pipe,” may install a plastic EFV.

  1.3. Only personnel qualified as described in applicable welding procedures may install a steel EFV.

  1.4. See Appendix C for an EFV installation and replacement matrix.

  1.5. Exceptions to the guidelines listed in this GDS may be granted by Standards Engineering.

  2 Applications for EFVs

  2.1. Table 1 describes when EFVs must be installed on new, replaced, repaired, altered, and transferred service lines, except as noted in Step 2.2.

  A. In certain scenarios an EFV is required only when there is a new complete service line or new stub service. This does not include repairs, alterations, replacements, or stub completions. It is recommended to install an EFV on existing or replaced services or stub completions, where practical (e.g., installing an EFV would not require upsizing the existing service).

  Table 1. Required EFV Scenarios

  Service Type	Total Connected Load in Standard Cubic Feet per Hour (scfh)	Col3
  Service Type	0–1400	1401–5000
  Single or branched service to single-family residence(s)1	EFV required	EFV required
  Single or branched service to multifamily building(s)1	EFV required	EFV required for new service line2
  Branched service to single-family residence and multifamily building1	EFV required	EFV required for new service line2
  Single service to single commercial meter	EFV required	EFV required for new service line2
  Any other service line (single or branched)	EFV required for new service line2	EFV required for new service line2

  1. Step 6.2, “Branched Service Lines” describes appropriate EFV locations on branches.
  2. Step 2.1.A provides an explanation on what is a new service line.

  Printed copies of this document might be out of date. The Technical Information Library (TIL) has the current version.

  PG&E Internal Information “PG&E” refers to Pacific Gas and Electric Company, a subsidiary of PG&E Corporation.

  ©2021 Pacific Gas and Electric Company. All rights reserved.

  Page 1 of 19

  Excess Flow Valves A-93.3

  Publication Date: 10/20/2021 Effective Date: 01/01/2022 Rev. 9c

  2.2. An EFV is not required in the following situations:

• CMC § 3663.3 High relevance — show source text

  (n) A high oil temperature interlock for oil or liquid fuel requiring preheating.

  (o) The burner oil pump shall automatically not operate or rotate while the alternate fuel is firing.

  (p) A pressure-relief valve shall be provided between safety shutoff valves and between pump and safety valves where an integral valve is used with a pump.

  (q) A separate relief device is required on each transfer

  pump.

  (3) One million to 2 499 999 Btu/h (293 kW to 732 kW) input per burner.

  (a) One approved manual shutoff valve lever handle.

  (b) One approved fuel-oil filter, installed on the supply piping.

  (c) Two safety shutoff valves in series with a combined flame failure response and valve closing time not to exceed 5 seconds with strainer directly before the valves.

  (d) Programmed electronic flame safeguard including proven low-fire start, manual reset lockout, 100 percent shutoff (both pilot and main burner), and a separately supervised and proven pilot.

  Flame-sensing systems utilizing a UV scanner shall prove pilot and interrupt ignition spark prior to main burner valves being energized.

  (e) Two controls, one operating and one high limit, activated by temperature or pressure.

  (f) Burners relying on mechanical means to provide air for combustion shall have actual proof-of-air interlock device.

  (g) Power burners shall include proven prepurge of not less than 60 seconds at high-fire damper settings. This prepurge shall occur before every burner cycle, regardless of reason.

  (h) Installations with dampered combustion air openings shall prove damper open position before trial for burner ignition.

  (i) Vent dampers and flue dampers shall be interlocked to prevent burner ignition unless safely open.

  (j) One high oil or liquid fuel-pressure interlock, reset from flame safeguard or manually.

  400 2025 CALIFORNIA MECHANICAL CODE

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

  APPENDIX C

  (k) Where hot water or steam, two low water cutoffs.

  (l) An atomizing medium proving switch.

  (m) A low oil temperature switch for oil or liquid fuel requiring preheating.

  (n) A high oil temperature interlock for oil or liquid fuel requiring preheating.

  (o) The burner oil pump shall automatically not operate or rotate while the alternate fuel is firing.

  (p) A pressure-relief valve shall be provided between safety shutoff valves and between pump and safety valves where an integral valve is used with a pump.

  (q) A separate relief device is required on each transfer

  pump.

  (r) One low oil or liquid fuel-pressure interlock, reset from flame safeguard or manually.

  (s) Burners with automatic controls, prepurge, proofof-closure, modulation, or postpurge shall not use relays external to the flame safeguard to accomplish these functions.

  (4) Two million five hundred thousand to 12 499 999 Btu/h (733 kW to 3663.3 kW) per burner.

  (a) One approved manual shutoff valve lever handle.

  (b) One approved fuel-oil filter, installed on the supply piping.

  (c) Two safety shutoff valves in series, with a combined flame failure response and valve closing time not to exceed 5 seconds with strainer directly before the valves.

• CMC § 4170P-52 Medium relevance — show source text

  • Utility Procedure TD-4170P-52, “Mechanical Fitting Connections for Polyethylene Pipe (Threaded Compression Transitions)”

    • Utility Procedure TD-4170P-53, “Mechanical Fitting Connections for Polyethylene Pipe (Bolt-On Saddle)”

  Construction Materials

  1. Heat Fusion Fittings are listed in GDS B-90 and GDS B-90.1.

  2. Electrofusion Fittings are listed in GDS B-90.3.

  3. PE-to-PE mechanical connections are listed in the following standards:

  • GDS B-90.1

  • GDS B-91

  • GDS B-91.1

  4. Transition fittings are listed in the following standards:

  • GDS B-54, “Compression Couplings”

  • GDS B-91

  • GDS B-91.1

  5. Excess flow valves are listed in GDS A-93.3.

  6. Plastic valves are listed in GDS F-90, “Polyethylene (PE) Valves.”

  7. Prefabricated risers are listed in GDS A-91.

  Printed copies of this document might be out of date. The Technical Information Library (TIL) has the current version.

  PG&E Internal Information “PG&E” refers to Pacific Gas and Electric Company, a subsidiary of PG&E Corporation.

  ©2021 Pacific Gas and Electric Company. All rights reserved.

  Page 19 of 19

  GAS DESIGN STANDARD

  EXCESS FLOW VALVES

  A-93.3

  Publication Date: 10/20/2021 Effective Date: 01/01/2022 Rev. 9c

  Purpose and Scope

  This gas design standard (GDS) provides specifications and design information for selecting and installing polyethylene (PE) and steel excess flow valves (EFVs).

  1 General Information

  1.1. EFVs are manufactured in accordance with American Society for Testing and Materials (ASTM International) F2138, “Standard Specification for Excess Flow Valves for Natural Gas Service,” and ASTM F1802, “Standard Test Method for Performance Testing of Excess Flow Valves.”

  1.2. Only personnel qualified as described in GDS D-34, “Qualifications for Joining Polyethylene Pipe,” may install a plastic EFV.

  1.3. Only personnel qualified as described in applicable welding procedures may install a steel EFV.

  1.4. See Appendix C for an EFV installation and replacement matrix.

  1.5. Exceptions to the guidelines listed in this GDS may be granted by Standards Engineering.

  2 Applications for EFVs

  2.1. Table 1 describes when EFVs must be installed on new, replaced, repaired, altered, and transferred service lines, except as noted in Step 2.2.

  A. In certain scenarios an EFV is required only when there is a new complete service line or new stub service. This does not include repairs, alterations, replacements, or stub completions. It is recommended to install an EFV on existing or replaced services or stub completions, where practical (e.g., installing an EFV would not require upsizing the existing service).

  Table 1. Required EFV Scenarios

• CMC § 12-16 Medium relevance — show source text

  12-16-1 ENGINEERING REGULATIONS—QUALITY AND

  DESIGN OF THE MATERIALS OF CONSTRUCTION

  CALIFORNIA STANDARD FOR EARTHQUAKE-ACTUATED AUTOMATIC GAS SHUTOFF SYSTEMS (SEE CCR TITLE 24, PART 2, CHAPTERS 16 AND 16A, AND CCR TITLE 24, PART 5, CHAPTER 12) STANDARD 12-16-1

  DIVISION OF THE STATE ARCHITECT

  Authority: Sections 19180–19183, Health and Safety Code. Reference: Section 19182, Health and Safety Code.

  DIVISION 1—CONSTRUCTION

  SCOPE

  Sec. 12-16-101. The American Society of Civil Engineers (ASCE) requirements for “Earthquake-Actuated Automatic Gas Shutoff Devices,” ANSI/ASCE/SEI 25-16 (copyright 2016 by ASCE), shall be the applicable standard used by the Division of the State Architect for the certification of these devices.

  Sec. 12-16-101.1. Each installation of a customer-owned device that satisfies this standard shall be in accordance with the California Plumbing Code (CCR Title 24, Part 5).

  2025 CALIFORNIA REFERENCED STANDARDS CODE 101

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

  102 2025 CALIFORNIA REFERENCED STANDARDS CODE

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

  12-16-2 ENGINEERING REGULATIONS—QUALITY AND

  DESIGN OF THE MATERIALS OF CONSTRUCTION

  CALIFORNIA STANDARD FOR RESIDENTIAL EXCESS FLOW ACTUATED AUTOMATIC GAS SHUTOFF VALVES (SEE CCR TITLE 24, PART 5, CHAPTER 12) STANDARD 12-16-2

  DIVISION OF THE STATE ARCHITECT

  Authority: Sections 19200–19204, Health and Safety Code. Reference: Sections 19201.5 and 19202, Health and Safety Code.

  DIVISION 1—CONSTRUCTION

  SCOPE

  Sec. 12-16-201. The American Society for Testing and Materials (ASTM) F2138-12(2017) Standard Specification for Excess Flow Valves for Natural Gas Service, and the American National Standards Institute (ANSI) Z21.93-2017/CSA 6.30-2017 Excess Flow Valves for Natural and LP Gas with Pressure up to 5 psig, shall be the applicable standards used by the Division of the State Architect for certification of these devices.

  Sec. 12-16-201.1. Each installation of a customer-owned device that satisfies this standard shall be in accordance with the California Plumbing Code (CCR Title 24, Part 5).

  2025 CALIFORNIA REFERENCED STANDARDS CODE 103

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

  104 2025 CALIFORNIA REFERENCED STANDARDS CODE

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

  12-31C RADIATION SHIELDING STANDARDS

  STANDARD 12-31C-1

  DEPARTMENT OF HEALTH SERVICES

• CMC § 90.2 Medium relevance — show source text

  Compliance Requirement/Regulatory Commitment

  NA

  References

  Plastic Main and Service Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-90 Locating Wire Installation for Direct Burial Plastic Mains and Services . . . . . . . . . . . . . . . . . . . . A-90.2 Approved “Mark and Locate” Instruments, Equipment, Accessories, and Products . . . . . . . . . M-60 Gas Applicant Design Manual

  Appendices

  NA

  Attachments

  NA

  Revision Notes

  Revision 03 has the following changes:

  1. Added Notes for Replacement of Existing Branch Services and for Installation of New Branch Services.

  2. Added Notes for Subdivisions.

  3. Added Exceptions.

  4. Added Method C and D. Reversed order of A and B.

  5. This document is part of Change 66.

  Asset Type: Gas Transmission and Distribution Function: Design Document Contact: Gas Design Standard Responsibility List

  Page 4 of 4 PG&E Internal Information, SL2 © 2013 Pacific Gas & Electric Company. All Rights Reserved. Prepared by: AAJ7

  GAS DESIGN STANDARD

  CURB VALVES

  A-43.2

  Publication Date: 04/15/2020 Effective Date: 07/15/2020 Rev. 5

  Purpose and Scope

  This gas design standard (GDS) provides requirements and installation instructions for service valves installed in curb areas. Curb valves are to be installed in accordance with Code of Federal Regulations (CFR) Title 49, Transportation, Part 192—Transportation of Natural and Other Gas by Pipeline: Minimum Federal Safety Standards, Section (§) 192.385, “Manual service line shut-off valve installation.”

  1 Installation Guidelines

  1.1. Use an excess flow valve (EFV) instead of, or in addition to, a curb valve, when feasible. See GDS A-93.3, “Excess Flow Valves,” and criteria in Step 1.2 for additional information.

  1.2. Use a curb valve on every new or replaced service line when any of the following conditions exist:

  A. The total meter capacity exceeds 1000 standard cubic feet per hour, and an EFV is not required and not installed.

  (1) Valves meeting the above criteria are critical isolation valves. See Attachment 1, “Installation Guidance” for additional guidance and requirements.

• CMC § 93.3 Medium relevance — show source text

  • Integrity

  • Storage

  • Retention and Disposition

  • Classification and Protection

  Printed copies of this document might be out of date. The Technical Information Library (TIL) has the current version.

  PG&E Internal Information “PG&E” refers to Pacific Gas and Electric Company, a subsidiary of PG&E Corporation.

  ©2021 Pacific Gas and Electric Company. All rights reserved.

  Page 13 of 19

  Excess Flow Valves A-93.3

  Publication Date: 10/20/2021 Effective Date: 01/01/2022 Rev. 9c

  References

  American Society for Testing and Materials (ASTM International) A53, “Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless”

  American Society for Testing and Materials (ASTM International) F1802, “Standard Test Method for Performance Testing of Excess Flow Valves”

  American Society for Testing and Materials (ASTM International) F2138, “Standard Specification for Excess Flow Valves for Natural Gas Service”

  Gas Design Standard A-34, “Piping Test Design Requirements”

  Gas Design Standard A-38, “Purging Gas Facilities”

  Gas Design Standard A-42, “Standard Branch Service Installation”

  Gas Design Standard A-43.2, “Curb Valves”

  Gas Design Standard D-34, “Qualifications for Joining Polyethylene Pipe”

  Gas Design Standard H-10, “High-Pressure Regulator-Type Stations and Farm Tap Regulator Sets”

  Gas Design Standard J-10.1, “Diaphragm Meter Capacities”

  Gas Design Standard J-20, “Rotary Meter Capacity – At Standard and Elevated Delivery Pressures”

  Utility Standard TD-4801S, “Service Replacement Criteria”

  Appendices

  Appendix A, “Pressure Drop Across EFVs”

  Appendix B, “Calculating Equivalent Lengths of Plastic Pipe”

  Appendix C, “EFV Installation and Replacement Matrix”

  Attachments

  Attachment 1, "Excess Flow Valve (EFV) Calculator"

  Printed copies of this document might be out of date. The Technical Information Library (TIL) has the current version.

  Page 14 of 19 “PG&E” refers to Pacific Gas and Electric Company, a subsidiary of PG&E Corporation.

  ©2021 Pacific Gas and Electric Company. All rights reserved.

  PG&E Internal Information

  Excess Flow Valves A-93.3

  Publication Date: 10/20/2021 Effective Date: 01/01/2022 Rev. 9c

  Revision Notes

  Revision 9c has the following changes:

  1. Updated Section 3 as follows:

  a. In Step 3.6.A, deleted any mention of Honeywell Perfection EFVs (except in Step 3.6.A.4), GasBreaker, and plastic Lyall. Added “with plain ends,” “with socket ends,” and “incorporated into plastic electrofusion couplings.”

  b. Added new step (Step 3.10) to refer to Appendix A.

  2. Completely revised Section 4, including the following:

  a. Grouped plastic EFVs by connection type rather than by manufacturer.

  b. Added manufacturer's part numbers to the tables.

  c. Added three additional GasBreaker EFVs with plain ends.

• CMC § 5.8.8.1 Medium relevance — show source text

  ** The discharge stacks, vents, or outlet parts of all pressure relieving and pressure limiting devices shall be located so that gas is safely discharged to the outdoors. Discharge stacks or vents shall be designed to prevent the entry of water, insects, or other foreign material that could cause blockage. The discharge stack or vent line shall be at least the same size as the outlet of the pressure relieving device. [NFPA 54:5.8.8.1, 5.8.8.2] 1308.9.7 Size of Fittings, Pipe, and Openings. The fittings, pipe, and openings located between the system to be protected and the pressure relieving device shall be sized to prevent hammering of the valve and to prevent impairment of relief capacity. [NFPA 54:5.8.9] 1308.10 Backpressure Protection. Protective devices shall be installed as close to the equipment as practical where the design of equipment connected is such that air, oxygen, or standby gases could be forced into the gas supply system. Gas and air combustion mixers incorporating double diaphragm “zero” or “atmosphere” governors or regulators shall require no further protection unless connected directly to compressed air or oxygen at pressures of 5 psi (34 kPa) or more. [NFPA 54:5.9.1.1, 5.9.1.2]

  1308.10.1 Protective Devices. Protective devices shall include but not be limited to the following:

  (1) Check valves.

  (2) Three-way valves (of the type that completely closes one side before starting to open the other side).

  (3) Reverse flow indicators controlling positive shutoff valves.

  (4) Normally closed air-actuated positive shutoff pressure regulators. [NFPA 54:5.9.2] 1308.11 Low-Pressure Protection. A protective device shall be installed between the meter and the appliance or equipment if the operation of the appliance or equipment is such that it could produce a vacuum or a dangerous reduction in gas pressure at the meter. Such protective devices include, but are not limited to, mechanical, diaphragm-operated, or electrically operated low-pressure shutoff valves. [NFPA 54:5.10]

  1308.12 Shutoff Valves. Shutoff valves shall be selected in

  accordance with Table 1308.12. Shutoff valves of size 1 inch

  (25 mm) National Pipe Thread and smaller shall be listed and labeled. Where used outdoors, such use shall be in accordance with the manufacturer’s recommendation. [NFPA 54:5.11]

  «

  «

  282 2025 CALIFORNIA MECHANICAL CODE

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

  FUEL GAS PIPING

  Exceptions: (1) A regulator and vent limiting means combination listed as complying with CSA/ANSI Z21.80/CSA 6.22, shall not be required to be vented to the outdoors.

  (2) A listed gas appliance regulator factory equipped with a vent limiting device is not required to be vented to the outdoors.

• CMC § 1406.2.1.5 Medium relevance — show source text

  1406.2.1.5 Emergency Shutoff Valves. Readily accessible manual or automatic remotely activated fail-safe emergency shutoff valves shall be installed on piping and tubing other than waste lines at the following locations:

  (1) At branch connections into the fabrication area.

  (2) At entries into exit corridors. Excess flow valves shall be installed as required by the fire code.

  1406.2.1.6 Electrical Wiring. Electrical wiring and equipment located in the piping space shall be approved for Class I, Division 2, Hazardous Locations.

  Exception: Occasional transverse crossing of the corridors by supply piping that is enclosed within the corridor need not comply with Section 1406.2.1.1 through Section 1406.2.1.6.

  1406.3 Special Requirements for HPP Gases. In addition to other requirements of this section, HPP gases shall comply with this subsection and the fire code.

  1406.3.1 Special Provisions. Where HPP supply gas is carried in pressurized piping, a fail-safe system shall shut off flow due to a rupture in the piping. Where the piping originates from outside the building, the valve shall be located outside the building as close to the bulk source as practical.

  1406.3.2 Piping and Tubing Installation. Piping and tubing shall be installed in accordance with approved standards. Supply piping for hazardous production materials having a health hazard ranking of 3 or 4 shall have welded connections throughout, unless an exhausted enclosure is provided.

  Exception: Material that is incompatible with ferrous piping shall be permitted to be installed in nonmetallic piping with approved connections.

  1406.3.3 Gas-Detection System. Where hazardous production material gas is used or dispensed and the physiological warning properties of the gas are at a higher level than the accepted permissible exposure limit (PEL) of the gas, a continuous gas-monitoring system shall be provided to detect the presence of the short-term hazard condition. Where dispensing occurs and flammable gases or vapors are capable of being present in quantities in excess of 25 percent of the lower explosive limit (LEL), a continuous gas-monitoring system shall be connected to the emergency control station. The maximum permitted time-weighted average exposures to be utilized shall be as published in 29 CFR 1910.1000.

  336 2025 CALIFORNIA MECHANICAL CODE

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

  CALIFORNIA MECHANICAL CODE – MATRIX ADOPTION TABLE

  CHAPTER 15 – SOLAR ENERGY SYSTEMS

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

  |Adopting Agency
  Adopt Entire Chapter
  Adopt Entire Chapter as
  amended (amended sections
  listed below)
  Adopt only those sections
  that are listed below
  Chapter/Section
  1502.

• CMC § 93.3 Medium relevance — show source text

  Printed copies of this document might be out of date. The Technical Information Library (TIL) has the current version.

  Page 12 of 19 “PG&E” refers to Pacific Gas and Electric Company, a subsidiary of PG&E Corporation.

  ©2021 Pacific Gas and Electric Company. All rights reserved.

  PG&E Internal Information

  Excess Flow Valves A-93.3

  Publication Date: 10/20/2021 Effective Date: 01/01/2022 Rev. 9c

  Target Audience

  Gas distribution engineering and estimating personnel, maintenance and construction personnel, general construction personnel, contractors, applicant designers, and inspectors.

  Definitions

  Branch service line A gas service line that is not directly connected to a gas main but has another service line as its source of supply.

  Farm tap regulator set A pressure regulator set, including both single and multiple stages of pressure regulation, that controls pressure to a service line.

  Nominal operating pressure (NOP)

  The operating pressure of a system that is generally the set point of the working regulator.

  Total connected load Total demand of all gas appliances operating simultaneously and at full capacity.

  Compliance Requirement / Regulatory Commitment

  Code of Federal Regulations (CFR) Title 49, Transportation, Part 192—Transportation of Natural and Other Gas by Pipeline: Minimum Federal Safety Standards, Section 192.381, “Service lines: Excess flow valve performance standards.”

  Code of Federal Regulations (CFR) Title 49, Transportation, Part 192—Transportation of Natural and Other Gas by Pipeline: Minimum Federal Safety Standards, Section 192.383, “Excess flow valve installation.”

  Records and Information Management:

  Information or records generated by this procedure must be managed in accordance with the Enterprise Records and Information (ERIM) Policy, Standards and Enterprise Records Retention Schedule (ERRS). Refer to GOV-7101S, “Enterprise Records and Information Management Standard,” and related standards. Management of records includes, but is not limited to:

  • Integrity

  • Storage

  • Retention and Disposition

  • Classification and Protection

  Printed copies of this document might be out of date. The Technical Information Library (TIL) has the current version.

  PG&E Internal Information “PG&E” refers to Pacific Gas and Electric Company, a subsidiary of PG&E Corporation.

  ©2021 Pacific Gas and Electric Company. All rights reserved.

  Page 13 of 19

  Excess Flow Valves A-93.3

  Publication Date: 10/20/2021 Effective Date: 01/01/2022 Rev. 9c

  References

  American Society for Testing and Materials (ASTM International) A53, “Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless”

  American Society for Testing and Materials (ASTM International) F1802, “Standard Test Method for Performance Testing of Excess Flow Valves”

  American Society for Testing and Materials (ASTM International) F2138, “Standard Specification for Excess Flow Valves for Natural Gas Service”

  Gas Design Standard A-34, “Piping Test Design Requirements”

  Gas Design Standard A-38, “Purging Gas Facilities”

  Gas Design Standard A-42, “Standard Branch Service Installation”

  Gas Design Standard A-43.2, “Curb Valves”

  Gas Design Standard D-34, “Qualifications for Joining Polyethylene Pipe”

  Gas Design Standard H-10, “High-Pressure Regulator-Type Stations and Farm Tap Regulator Sets”

• CMC § 12-16 Medium relevance — show source text

  CALIFORNIA STANDARD FOR RESIDENTIAL EXCESS FLOW ACTUATED AUTOMATIC GAS SHUTOFF VALVES (SEE CCR TITLE 24, PART 5, CHAPTER 12) STANDARD 12-16-2

  DIVISION OF THE STATE ARCHITECT

  Authority: Sections 19200–19204, Health and Safety Code. Reference: Sections 19201.5 and 19202, Health and Safety Code.

  DIVISION 1—CONSTRUCTION

  SCOPE

  Sec. 12-16-201. The American Society for Testing and Materials (ASTM) F2138-12(2017) Standard Specification for Excess Flow Valves for Natural Gas Service, and the American National Standards Institute (ANSI) Z21.93-2017/CSA 6.30-2017 Excess Flow Valves for Natural and LP Gas with Pressure up to 5 psig, shall be the applicable standards used by the Division of the State Architect for certification of these devices.

  Sec. 12-16-201.1. Each installation of a customer-owned device that satisfies this standard shall be in accordance with the California Plumbing Code (CCR Title 24, Part 5).

  2025 CALIFORNIA REFERENCED STANDARDS CODE 103

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

  104 2025 CALIFORNIA REFERENCED STANDARDS CODE

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

  12-31C RADIATION SHIELDING STANDARDS

  STANDARD 12-31C-1

  DEPARTMENT OF HEALTH SERVICES

  Authority: Sections 102, 208 and 25811.

  Reference: Sections 102, 208 and 436.5.

  ALL HEALING ARTS X-RAY INSTALLATIONS

  Sec. 12-31C-101. All radiation shielding barriers in rooms and enclosures housing radiation machines shall comply with the mandatory standards and appendices in Report No. 35, “Dental X-RAY Protection”; Report 49, “Structural Shielding Design and Evaluation for Medical use of X-rays and Gamma Rays of Energies up to 10 MeV”; and Report No. 51, “Radiation Protection Design Guidelines for 0.1-100 MeV Particle Accelerator Facilities.” Published by the National Council on Radiation Protection and Measurements, 7910 Woodmont Avenue, Bethesda, Maryland 20814.

  2025 CALIFORNIA REFERENCED STANDARDS CODE 105

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

  106 2025 CALIFORNIA REFERENCED STANDARDS CODE

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

  12-71 AIR FILTERS

  STANDARD 12-71-1

  STATE FIRE MARSHAL

  DESCRIPTION OF TEST APPARATUS, METHOD AND CLASSIFICATION REQUIREMENTS FOR AIR FILTERS

  Sec. 12-71-100.

  (a) Test apparatus.

  1. The test duct, made of M.S. gage galvanized sheet metal reinforced with angle irons, is 21 inches square (13 548 mm [2] ) and 13 [1] / 2 feet (4114 mm) long.
• CMC § 7.3 Medium relevance — show source text

  3|7.3|9.9|14.6| |26|NP|NP|NP|NP|13.2|22.4|NP|NP|5.0|8.5|11.4|16.9| |28|NP|NP|NP|NP|15.1|25.7|NP|NP|5.7|9.7|13.1|19.4| |30|NP|NP|NP|NP|17.2|NP|NP|NP|6.5|11.0|14.9|22.0| |32|NP|NP|NP|NP|19.4|NP|NP|NP|7.3|12.4|16.8|24.8| |34|NP|NP|NP|NP|21.7|NP|NP|NP|8.2|13.9|18.8|NP| |36|NP|NP|NP|NP|24.1|NP|NP|NP|9.1|15.4|20.9|NP| |For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 gallon per minute = 0.063 L/s, 1 pound per square inch = 6.895 kPa.
  NP = Not Permitted. Pressure loss exceeds reasonable limits.
  a. Values are applicable for underground piping materials listed in_ the California Plumbing Code_ and are based on an SDR of 11 and a Hazen Williams C Factor of 150.
  b. Values include the following length allowances for fittings: 25-percent length increase for actual lengths up to 100 feet and 15-percent length increase for actual lengths over
  100 feet.
  c. Flow rate from Section P2904.4.2. Add 5 gpm to the flow rate required by Section_R309.3.4.2_ where the water service pipe supplies more than one dwelling.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 gallon per minute = 0.063 L/s, 1 pound per square inch = 6.895 kPa.
  NP = Not Permitted. Pressure loss exceeds reasonable limits.
  a. Values are applicable for underground piping materials listed in_ the California Plumbing Code_ and are based on an SDR of 11 and a Hazen Williams C Factor of 150.
  b. Values include the following length allowances for fittings: 25-percent length increase for actual lengths up to 100 feet and 15-percent length increase for actual lengths over
  100 feet.
  c. Flow rate from Section P2904.4.2. Add 5 gpm to the flow rate required by Section_R309.3.4.2_ where the water service pipe supplies more than one dwelling.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 gallon per minute = 0.063 L/s, 1 pound per square inch = 6.895 kPa.
  NP = Not Permitted. Pressure loss exceeds reasonable limits.
  a. Values are applicable for underground piping materials listed in_ the California Plumbing Code_ and are based on an SDR of 11 and a Hazen Williams C Factor of 150.
  b. Values include the following length allowances for fittings: 25-percent length increase for actual lengths up to 100 feet and 15-percent length increase for actual lengths over
  100 feet.
  c. Flow rate from Section P2904.4.2.

• CMC § 3663.4 Medium relevance — show source text

  (5) More than 12 500 000 Btu/h (3663.4 kW) per burner inputs. These burners shall comply with the requirements of the appropriate standards listed in Chapter 18 and the following:

  (a) One approved manual shutoff valve lever handle.

  (b) One approved fuel-oil filter, installed on the supply piping.

  (c) Two safety shutoff valves in series, one with proof of closure, with a combined flame failure response and valve closing time not to exceed 2 seconds with strainer directly before the valves.

  (d) Programmed electronic flame safeguard including proven low-fire start, manual reset lockout, 100 percent shutoff (both pilot and main burner), and a separately supervised and proven pilot.

  Flame-sensing systems utilizing a UV scanner shall prove pilot and interrupt ignition spark prior to main burner valves being energized.

  (e) Two controls, one operating and one high limit, activated by temperature or pressure.

  (f) Burners relying on mechanical means to provide air for combustion shall have actual proof-of-air interlock device.

  (g) Power burners must include proven prepurge of not less than 60 seconds at high-fire damper settings. This prepurge shall occur before every burner cycle, regardless of reason.

  (h) Installations with dampered combustion air openings shall prove damper open position before trial for burner ignition.

  (i) Vent dampers and flue dampers shall be interlocked to prevent burner ignition unless safely open.

  (j) One high oil or liquid fuel-pressure interlock; reset from flame safeguard or manually.

  2025 CALIFORNIA MECHANICAL CODE 401

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

  APPENDIX C

  (k) A manual firing cock.

  (l) Where hot water or steam, two low water cut-offs.

  (m) An atomizing medium proving switch.

  (n) A low oil temperature switch for oil or liquid fuel requiring preheating.

  (o) A high oil temperature interlock for oil or liquid fuel requiring pre-heating.

  (p) A separate firing rate control valve.

  (q) The burner oil pump shall automatically not operate or rotate while the alternate fuel is firing.

  (r) A pressure-relief valve shall be provided between safety shutoff valves and between pump and safety valves where an integral valve is used with a pump.

  (s) A separate relief device is required on each transfer

  pump.

  (t) One low oil or liquid fuel-pressure interlock, reset from flame safeguard or manually.

  (u) Burners with automatic controls, prepurge, proofof-closure, modulation, or postpurge shall not use relays external to the flame safeguard to accomplish these functions.

  (6) Shutoff Valve.

  (a) Oil or liquid fuel burner installations shall include a non-electric shutoff valve that is held open by a fusible link designed to close at 165°F (74°C), installed near the burner in the same room as the burner. This shall prevent the flow of oil or liquid fuel to the burner through the supply pipe. A check valve is required in the return line if the tank is higher than the burner.

  402 2025 CALIFORNIA MECHANICAL CODE

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

  CALIFORNIA MECHANICAL CODE – MATRIX ADOPTION TABLE

• CMC § 1308.9.2 Medium relevance — show source text

  1308.9.2 Construction and Installation. All overpressure protection devices shall meet the following requirements:

  (1) Be constructed of materials so that the operation of the device is not impaired by corrosion of external parts by the atmosphere or of internal parts by the gas.

  (2) Be designed and installed so they can be operated to determine whether the valve is free. The devices shall also be designed and installed so they can be tested to determine the pressure at which they operate and be examined for leakage when in the closed position. [NFPA 54:5.8.4]

  1308.9.3 External Control Piping. External control piping shall be designed and installed so that damage to the control piping of one device does not render both the regulator and the overpressure protective device inoperative. [NFPA 54:5.8.5]

  1308.9.4 Setting. Each pressure limiting or pressure relieving device shall be set so that the gas pressure supplied to the connected appliance(s) does not exceed the limits specified in Section 1308.8 and Section 1308.8.1.

  [NFPA 54:5.8.6]

  1308.9.5 Unauthorized Operation. Where unauthorized operation of any shutoff valve could render a pres

  «

  «

  «

  «

  «

  «

  2025 CALIFORNIA MECHANICAL CODE 281

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

  FUEL GAS PIPING

  TABLE 1308.12

  MANUAL GAS VALVE STANDARDS

  [NFPA 54: TABLE 5.11]

  SHUTOFF VALVE APPLICATION	STANDARDS
  Appliance shutoff valve up to1_/_2 psi	CSA/ANSI Z21.15/CSA 9.1
  Appliance shutoff valve up to1_/_2 psi	ASME B16.44
  Appliance shutoff valve up to1_/_2 psi	ASME B16.33 marked 125 G
  Appliance shutoff valve up to1_/_2 psi	CSA/ANSI LC 4/CSA 6.32
  Valve up to1_/_2 psi	ASME B16.44
  Valve up to1_/_2 psi	ASME B16.33 marked 125 G
  Valve up to1_/_2 psi	CSA/ANSI LC 4/CSA 6.32
  Valve up to 2 psi	ASME B16.44 labeled 2G
  Valve up to 2 psi	ASME B16.33 marked 125 G
  Valve up to 2 psi	CSA/ANSI LC 4/CSA 6.

• CMC § 7.8.1.1 Medium relevance — show source text

  ** System shutoff valves shall be readily accessible for operation and installed so as to be protected from physical damage. System shutoff valves shall be marked with a metal tag or other permanent means attached by the installing agency so that the gas piping systems supplied through them can be readily identified. [NFPA 54:7.8.1.1, 7.8.1.2]

  1310.11.1.1 Shutoff Valves for Multiple House Lines. In multiple-tenant buildings supplied through a master meter, through one service regulator where a meter is not provided, or where meters or service regulators are not readily accessible from the appliance or equipment location, an individual shutoff valve for each apartment or tenant line shall be provided at a convenient point of general accessibility. In a common system serving a number of individual buildings, shutoff valves shall be installed at each building. [NFPA 54:7.8.3.1] 1310.11.2 Emergency Shutoff Valves. An exterior shutoff valve to permit turning off the gas supply to each building in an emergency shall be provided. The emergency shutoff valves shall be plainly marked as such and their locations posted as required by the Authority Having Jurisdiction. [NFPA 54:7.8.3.2] 1310.11.3 Shutoff Valve for Laboratories. Each laboratory space containing two or more gas outlets installed on tables, benches, or in hoods in educational, research,

  2025 CALIFORNIA MECHANICAL CODE 287

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

  FUEL GAS PIPING

  commercial, and industrial occupancies shall have a single shutoff valve through which all such gas outlets are supplied. The shutoff valve shall be accessible, located within the laboratory or adjacent to the laboratory’s egress door, and identified. [NFPA 54:7.8.3.3] 1310.11.4 System Shutoff Valves. Where a system shutoff valve is installed, the valve shall comply with Section 1308.12. [NFPA 54:7.8.4]

  1310.12 Prohibited Devices. Devices shall not be placed within the interior of gas piping or fittings where such devices reduce the cross-sectional area or otherwise obstruct the free flow of gas, except where allowance in the piping system design has been made for such devices. [NFPA 54:7.9] 1310.13 Systems Containing Gas-Air Mixtures Out- side the Flammable Range. Where gas-air mixing machines are employed to produce mixtures above or below the flammable range, they shall be provided with stops to prevent adjustment of the mixture to within or approaching the flammable range. [NFPA 54:7.10] 1310.14 Systems Containing Flammable Gas-Air Mixtures. Systems containing flammable gas-air mixtures shall be in accordance with Section 1310.14.1 through Section 1310.14.6.

  1310.14.1 Required Components. A central premix system with a flammable mixture in the blower or compressor shall consist of the following components:

  (1) Gas-mixing machine in the form of an automatic gas-air proportioning device combined with a downstream blower or compressor.

  (2) Flammable mixture piping, minimum Schedule 40.

  (3) Automatic firecheck(s).

• CMC § 90.1 Medium relevance — show source text

  [ASHRAE 90.1:6.5.4.1]

  2025 CALIFORNIA MECHANICAL CODE 439

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

  APPENDIX E

  TABLE E 503.5.7.2

  PUMP FLOW CONTROL REQUIREMENTS

  [ASHRAE 90.1: TABLE 6.5.4.2]

  BOILER SYSTEM DESIGN INPUT, Btu/h	MINIMUM TURNDOWN RATIO
  ≥1 000 000 and≤5 000 000	3 to 1
  >5 000 000 and≤10 000 000	4 to 1
  >10 000 000	5 to 1

  »

  TABLE E 503.5.7

  BOILER TURNDOWN

  [ASHRAE 90.1: TABLE 6.5.4.1]

  For SI units: 1000 British thermal units per hour = 0.293 kW

  E 503.5.7.2 Hydronic Variable Flow Systems. Chilled- and hot-water distribution systems that include three or more control valves designed to modulate or step open and close as a function of load shall be designed for variable fluid flow and shall be capable of and configured to reduce pump flow rates to not more than the larger of 25 percent of the design flow rate or the minimum flow required by the heating/cooling equipment manufacturer for the proper operation of equipment. Individual or parallel pumps serving variable-flow heating-water or chilledwater systems, where the nameplate horsepower of the motor or combined parallel motors is not less than the power shown in Table E 503.5.7.2, shall have controls or devices that will result in pump motor demand of not more than 30 percent of design wattage at 50 percent of design water flow. The controls or devices shall be controlled as a function of desired flow or to

  maintain a minimum required differential pressure. Differential pressure shall be measured at or near the most remote heat exchanger or the heat exchanger requiring the greatest differential pressure. The differential pressure setpoint shall not exceed 110 percent of that required to achieve design flow through the heat exchanger. Where differential pressure control is used to comply with this section, and DDC systems are used, the setpoint shall be reset downward based on valve positions until one valve is nearly wide open.

  Exceptions:

  (1) Differential pressure set-point reset is not required where valve position is used to comply with Section E 503.5.7.4.

  (2) Variable-pump flow control is not required on heating-water pumps where more than 50 percent of annual heat is generated by an electric boiler.

  (3) Variable flow is not required for primary pumps in a primary/secondary system.

  (4) Variable flow is not required for a coil pump provided for freeze protection.

  (5) Variable flow is not required for heat recovery coil runaround loops. [ASHRAE 90.1:6.5.4.2]

• CMC § 1220.4.2 Medium relevance — show source text

  8|1220.4.2 – 1220.4.6| |1221.7|1221.6| |1308.2 – 1308.4.1|1308.3 – 1308.5.1| |Table 1308.3.1|Table 1308.4.1| |1308.4.2|1308.5.2| |1308.4.2.2 – 1308.6.4|1308.5.2.1 – 1308.7.3| |Table 1308.4.6.2|Table 1308.5.6.2| |1308.6.5 – 1308.13.1|1308.7.7 – 1308.14.1| |1312.1.2 – 1312.1.3|1312.1.1 – 1312.1.2| |Chapter 17|Appendix F| |Chapter 18|Chapter 17| |D 103.2|D 103.1| |E 503.5.6.7|E 503.5.6.6| |E 503.5.7.2 – E 503.5.7.6|E 503.5.7.1 – E 503.5.7.5| |Table E 503.5.7.2|Table E 503.5.7.1| |Table E 503.5.7.6|Table E 503.5.7.5| |Table E 503.5.10.1.2(1)|Table E 503.5.10(1)| |Table E 503.5.10.1.2(2)|Table E 503.5.10(2)| |E 503.5.10.1.2|E 503.5.10| |E 503.5.10.2 – E 503.5.10.2.2|E 503.5.10.1 – E 503.5.10.1.2| |E 503.5.12.1|E 503.5.12| |E 503.5.12.2|E 503.5.12.1| |E 503.6.5.4|E 503.6.5.4.1|

  xxii 2025 CALIFORNIA MECHANICAL CODE

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

  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 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:

• CMC § 5303.16.1 Medium relevance — show source text

  1, 5303.16.1, 5303.16.2, 5306.1, 5306.2, 5306.2.1, 5306.2.2, 5307.4.6, 5503.1.2, 5503.5.2, 5504.2.1.2, 5504.2.2.2, 5505.4.1, 5604.2, Table 5604.5.2(3), 5605.5, 5701.3, 5704.2.7.7, 5704.2.8.1, 5704.2.8.2, 5704.2.9.3, 5704.2.9.4, 5704.3.3.5, 5704.3.7.1, 5704.3.8, 5705.3.4, 5705.3.5.3, 5705.3.7.1, 5705.3.7.2, 5705.3.7.3, 5705.3.7.4, 5705.3.7.5.1, 5706.2.3, 5706.4.1, 5803.1.1, 5806.4.3, 5808.1, 5808.3, 5808.3.2, 5906.2.2, 5906.2.3, 5906.4.2, 6003.1.4.2, 6005.3.1, 6109.11.2, 6204.1.2, 6306.4, 6404.1.4, 6604.1

  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.

• CMC § 8.13.6.2 Medium relevance — show source text

  (1) Refrigerant compressors

  (2) Refrigerant pumps

  (3) Normally closed automatic refrigerant valves

  (4) Other unclassified electrical sources of ignition with apparent power rating greater than 1 kVA, where the apparent power is the product of the circuit voltage and current rating. [ASHRAE 15:8.13.6.2] 1106.11.7 Mechanical Equipment Control. Remote control of the mechanical equipment in the refrigerating machinery room shall be provided immediately outside the machinery room door solely for the purpose of shutting down the equipment in an emergency. Ventilation fans shall be on a separate electrical circuit and have a control switch located immediately outside the machinery room door. [ASHRAE 15:8.13.7] 1106.11.8 Refrigerant Detectors. Each refrigerating machinery room in accordance with Section 1106.11 shall contain one or more refrigerant detectors in accordance with Section 1106.11.9. The detector(s) sensing element shall be located in areas where refrigerant from a leak will concentrate, with one or more set points that activate responses in accordance with Section 1106.11.10 for alarms and Section 1106.11.11 for mechanical ventilation. Multiport-type devices shall be prohibited. {ASHRAE 15:8.13.8} 1106.11.9 Refrigerant Detectors Requirements. Refrigerant detectors required by Section 1106.11 shall meet all of the following conditions:

  (1) A refrigerant detector shall be capable of detecting each of the specific refrigerant designations in the machinery room.

  (2) The refrigerant detector shall activate responses within a time not to exceed a limit specified in Section 1106.11.10 and Section 1106.11.11 after exposure to refrigerant concentration exceeding a limit value specified in Section 1106.11.10 and Section 1106.11.11.

  (3) The refrigerant detector shall have a set point not greater than the applicable Occupational Exposure Limit (OEL) value in accordance with Table 1102.3. The applicable OEL value shall be the lowest OEL value for any refrigerant designation in the machinery room. For refrigerants that do not have an OEL value in Table 1102.3, use a value determined in accordance with the OEL as defined by ASHRAE 34 where approved by the Authority Having Jurisdiction.

  (4) The refrigerant detector shall have a set point not more than the applicable Refrigerant Concentration Limit (RCL) value in accordance with Table 1102.3. The applicable RCL value shall be the lowest RCL value for any refrigerant designation in the machinery room. For refrigerants that do not have a RCL value in Table 1102.3, use a value determined in accordance with the RCL as defined by ASHRAE 34 where approved by the Authority Having Jurisdiction.

  (5) The refrigerant detector shall provide a means for automatic self-testing and shall be in accordance with Section 1106.11.10.4. The refrigerant detector shall be tested during installation and annually thereafter in accordance with the fire code, or at an interval not exceeding the manufacturer’s installation instructions, whichever is less. Testing shall verify compliance with the alarm set points and response times per Section 1106.11.10 and Section 1106.11.11. [ASHRAE 15:8.13.9]

• CMC § 1106.2.6. Medium relevance — show source text

  (1) The space(s) containing the machinery is (are) separated from other occupancies by tight construction with tightfitting doors.

  (2) Access is restricted to authorized personnel.

  (3) Refrigerant detectors are installed with the sensing location and alarm level as required in refrigeration machinery rooms in accordance with Section 1106.2.6.

  (4) Open flames and surfaces exceeding 800°F (427°C) shall not be permitted where a Group A2, B2, A3, or B3 refrigerant, is used.

  (5) Electrical equipment that is in accordance with Class 1, Division 2, of NFPA 70 where the quantity of a Group A2, B2, A3, or B3 refrigerant in an independent circuit is capable of exceeding 25 percent of the lower flammability limit (LFL) upon release to the space based on the volume determined in accordance with Section 1104.2.1 through Section 1104.2.3.

  (6) Refrigerant containing parts in systems exceeding 100 horsepower (74.6 kW) compressor drive power, except evaporators used for refrigeration or dehumidification, condensers used for heating, control and pressure-relief valves for either, low-probability pumps, and connecting piping, are located in a machinery room or outdoors.

  [ASHRAE 15:7.2.2]

  1104.5 Flammable Refrigerants. The total of Group A2, B2, A3, and B3 refrigerants, other than Group A2L and B2L refrigerants shall not exceed 1100 pounds (498.9 kg) without approval by the Authority Having Jurisdiction. Institutional Occupancies shall comply with Section 1104.3. Machinery rooms required in accordance with Section 1106.0 based on flammability shall be constructed and maintained in accordance with Section 1106.2.1 through Section 1106.2.6 and Section 1106.11 for Group A2L and B2L refrigerants. 1104.6 Group A2L Refrigerants for Human Comfort. High-probability systems using Group A2L refrigerants for human comfort applications shall comply with this section.

  [ASHRAE 15:7.6]

  1104.6.1 Refrigerant Concentration Limits. Occupied spaces shall comply with the releasable charge limitations of the equipment listing and ASHRAE 15. Unoccupied spaces with refrigerant containing equipment, not including continuous piping or tubing, shall comply with the releasable charge limitations of the equipment listing or Section 1104.6.4. {ASHRAE 15:7.6.1-7.6.1.2}

  1104.6.2 Listing and Installation Requirements. Refrigeration systems shall be listed and shall be installed in accordance with listing, the manufacturer’s instructions, and any markings on the equipment restricting the installation. [ASHRAE 15:7.6.2]

  1104.6.2.1 Nameplate. The nameplate required by Section 1115.5 shall include a symbol indicating that a flammable refrigerant is used, as specified by the product listing. [ASHRAE 15:7.6.2.1]

  1104.6.2.2 Labeling. A label indicating a flammable refrigerant is used shall be placed adjacent to service ports and other locations where service involving components containing refrigerant is performed, as specified by the product listing.

• CMC § 90.1 Medium relevance — show source text

  [ASHRAE 90.1: TABLE 6.4.3.4.3]

  Col1	OUTDOOR AIR INTAKE (CFM/ft2)	Col3	EXHAUST/RELIEF (CFM/ft2)	Col5
  CLIMATE ZONE	NONMOTORIZED1	MOTORIZED	NONMOTORIZED3	MOTORIZED
  0, 1, 2	0, 1, 2	0, 1, 2	0, 1, 2	0, 1, 2
  Any height	20	4	20	4
  3	3	3	3	3
  Any height	20	10	20	10
  4, 5B, 5C	4, 5B, 5C	4, 5B, 5C	4, 5B, 5C	4, 5B, 5C
  Fewer than three stories	204	10	20	10
  Three or more stories	204	10	204	10
  5A, 6, 7, 8	5A, 6, 7, 8	5A, 6, 7, 8	5A, 6, 7, 8	5A, 6, 7, 8
  Fewer than three stories	204	4	20	4
  Three or more stories	204	4	204	4

  For SI units: 1 square foot = 0.0929 m [2], 1 cubic foot per minute = 0.00047 m [3] /s, 1 cubic foot per minute = 0.4719 L/s, 1 cubic foot per minute per square foot = 5.08 [(L/s)/m [2] ], 1 inch water gauge = 0.249 kPa

  Notes:

  1 When tested in accordance with AMCA 500D.

  2 Dampers smaller than 12 inches (305 mm) in height, width, or diameter need not be tested but shall be of the same design and construction as the smallest tested damper meeting the listed leakage rate requirement.

  3 Nonmotorized dampers smaller than 24 inches (610 mm) in height, width, or diameter shall be permitted to have a leakage rate of 40 CFM/ft 2 [0.203 (m 3 /s)/m 2 ].

  4 Where permitted by Section E 503.4.6.4.1, exception 2.

  2025 CALIFORNIA MECHANICAL CODE 425

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

  APPENDIX E

  (2) Systems serving zones where humidity levels are required to be maintained with precision of not more than ±5 percent relative humidity to comply with applicable codes or accreditation standards or as approved by the Authority Having Jurisdiction.

  [ASHRAE 90.1:6.4.3.6.2]

• CMC § 2024 Medium relevance — show source text

  Important Notices and Disclaimers The 2024 edition of the Uniform Mechanical Code is developed through a consensus standards development process approved by the American National Standards Institute. This process brings together volunteers representing varied viewpoints and interests to achieve consensus on mechanical issues. While the International Association of Plumbing and Mechanical Officials (IAPMO) administers the process and establishes rules to promote fairness in the development of consensus, it does not independently test, evaluate, or verify the accuracy of any information or the soundness of any judgments contained in its codes

  and standards.

  IAPMO disclaims liability for any personal injury, property, or other damages of any nature whatsoever, whether special, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, or reliance on this document. IAPMO also makes no guarantee or warranty as to the accuracy or completeness of any information published

  herein.

  In issuing and making this document available, IAPMO is not undertaking to render professional or other services for or on behalf of any person or entity. Nor is IAPMO undertaking to perform any duty owed by any person or entity to someone else. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care in any given circumstances.

  Updating IAPMO Codes Users of IAPMO codes should be aware that IAPMO codes may be amended from time to time through the issuance of Tentative Interim Amendments or corrected by Errata. IAPMO codes consist of the current edition of the document together with any Tentative Interim Amendments and any Errata in effect.

  To access information for a specific code or to determine whether an IAPMO code has been amended through the issuance of Tentative Interim Amendments or corrected by Errata, please visit the IAPMO codes information page on the IAPMO’s website (https://www.iapmo.org/code-development). The codes information page provides a list of IAPMO codes with up-to-date specific information including any issued Tentative Interim

  Amendments and Errata.

  x 2025 CALIFORNIA MECHANICAL CODE

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

  FOREWORD

  Origin and Development The industry has long recognized the advantages of a statewide adopted mechanical code. The first edition of the Uniform Mechanical Code [®] (UMC [®] ) was adopted by IAPMO in 1967. The widespread use of this code over the past five decades by jurisdictions throughout the United States and internationally is testament to its merit.

  Publishing of the 2003 Uniform Mechanical Code was a significant milestone because it was the first time in the history of the United States a mechanical code was developed through a true consensus process. The 2024 edition represents the most current approaches in the mechanical field and is the eighth edition developed under the ANSI consensus process. Contributions to the content of this code consists of diverse interests as consumers, enforcing authorities, installers/maintainers, labor, manufacturers, research/standards/testing laboratories, special experts, and users.

• CMC § 1.1.10 Medium relevance — show source text

  1.1.10 Availability of Codes. At least one complete copy each of Titles 8, 19, 20, 24, and 25 with all revisions shall be main- tained in the office of the building official responsible for the administration and enforcement of this code. Each state department concerned and each city, county, or city and county shall have an up-to-date copy of the code available for public inspection, see Health and Safety Code Section 18942(e)(1) and (2).

  1.1.11 Format. This part fundamentally adopts the Uniform Mechanical Code by reference on a chapter-by-chapter basis. When a specific chapter of the Uniform Mechanical Code is not printed in the code and is marked “Reserved”, such chapter of the Uniform Mechanical Code is not adopted as a portion of this code. When a specific chapter of the Uniform Mechanical Code is marked “Not adopted by the State of California” but appears in the code, it may be available for adoption by local ordinance.

  Note: Matrix Adoption Tables at the front of each chapter may aid the code user in determining which chapter or sections within a chapter are applicable to buildings under the authority of a specific state agency, but they are not to be considered regulatory.

  1.1.12 Validity. If any chapter, section, subsection, sentence, clause, or phrase of this code is for any reason held to be unconstitutional, contrary to statute, exceeding the authority of the state as stipulated by statutes or otherwise inoperative, such decision shall not affect the validity of the remaining portion of this code.

  1.2.0 Building Standards Commission.

  1.2.1 BSC. Specific scope of application of the agency responsible for enforcement, the enforcement agency, and the specific authority to adopt and enforce such provisions of this code, unless otherwise stated.

  (1) State Buildings for All Occupancies.

  Application – State buildings (all occupancies), including buildings constructed by the Trustees of the California State University (CSU) and the Regents of the University of California (UC) where no state agency has the authority to adopt building standards applicable to such buildings.

  Enforcing Agency – State or local agency specified by the applicable provisions of law.

  Authority Cited – Health and Safety Code Section 18934.5.

  2025 CALIFORNIA MECHANICAL CODE 5

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

  DIVISION I CALIFORNIA ADMINISTRATION

  Reference – Health and Safety Code, Division 13, Part 2.5, commencing with Section 18901.

  (2) University of California, California State Universities, and California Community Colleges.

  Application – Standards for lighting for parking lots and primary campus walkways at the University of Cali- fornia, California State Universities, and California Community Colleges.

  Enforcing Agency – State or local agency specified by the applicable provisions of law.

  Authority Cited – Government Code Section 14617.

  Reference – Government Code Section 14617.

• California Mechanical Code Medium relevance — show source text

  NA
  NA|NA
  NA
  NA
  NA
  NA|10
  10
  NA
  NA
  NA|18
  18
  17
  17
  16|26
  25
  24
  24
  23|55
  53
  52
  50
  49|99
  96
  93
  90
  88|156
  151
  147
  143
  139|326
  315
  306
  297
  289| |1100
  1200
  1300
  1400
  1500|1100
  1200
  1300
  1400
  1500|NA
  NA
  NA
  NA
  NA|NA
  NA
  NA
  NA
  NA|NA
  NA
  NA
  NA
  NA|15
  15
  14
  13
  13|22
  21
  20
  19
  18|46
  44
  42
  41
  39|84
  80
  76
  73
  71|132
  126
  120
  116
  111|274
  262
  251
  241
  232| |1600
  1700
  1800
  1900
  2000|1600
  1700
  1800
  1900
  2000|NA
  NA
  NA
  NA
  NA|NA
  NA
  NA
  NA
  NA|NA
  NA
  NA
  NA
  NA|13
  12
  12
  11
  11|18
  17
  17
  16
  16|38
  37
  36
  35
  

• California Mechanical Code Medium relevance — show source text

  
  2
  5
  10
  15
  20
  30|184
  175
  215
  265
  312
  360
  461|1168
  823
  806
  777
  750
  723
  670|647
  533
  521
  501
  481
  461
  426|229
  219
  269
  327
  379
  433
  541|1542
  1069
  1049
  1017
  985
  955
  895|852
  698
  684
  662
  638
  615
  574|312
  296
  366
  440
  507
  570
  704|1971
  1346
  1324
  1287
  1251
  1216
  1147|1056
  863
  846
  821
  794
  768
  720|454
  424
  524
  620
  702
  780
  937|2996
  1999
  1971
  1927
  1884
  1841
  1759|1545
  1308
  1283
  1243
  1205
  1166
  1101| |50|0
  2
  5
  10
  15
  20
  30|176
  168
  204
  253
  299
  345
  442|1292
  971
  953
  923
  894
  866
  809|704
  613
  602
  583
  562
  543
  502|220
  209
  257
  313
  363
  415
  521|1724
  1273
  1252
  1217
  1183
  1150
  1086|948
  811
  795
  765
  736
  708
  649|295
  280
  347
  418
  481
  544
  674|2223
  1615
  1591
  1551
  1512
  1473
  1399|1189
  1007
  991
  963
  934
  906
  848|428
  401
  496
  589
  668
  741
  892|3432
  2426
  2396
  2347
  2299
  2251
  2159|1818
  1509
  1490
  1455
  1421
  1387
  1318| |100|0
  2
  5

• California Mechanical Code Medium relevance — show source text

  
  2
  5
  10
  15
  20|190
  182
  224
  277
  325
  374|1053
  708
  692
  666
  640
  616|573
  468
  457
  437
  419
  400|238
  227
  279
  339
  393
  448|1379
  914
  896
  866
  838
  810|750
  611
  596
  570
  549
  526|326
  309
  381
  457
  526
  592|1751
  1146
  1126
  1092
  1060
  1028|927
  754
  734
  702
  677
  651|473
  443
  547
  646
  730
  808|2631
  1689
  1665
  1626
  1587
  1550|1346
  1098
  1074
  1037
  1005
  973| |30|0
  2
  5
  10
  15
  20
  30|184
  175
  215
  265
  312
  360
  461|1168
  823
  806
  777
  750
  723
  670|647
  533
  521
  501
  481
  461
  426|229
  219
  269
  327
  379
  433
  541|1542
  1069
  1049
  1017
  985
  955
  895|852
  698
  684
  662
  638
  615
  574|312
  296
  366
  440
  507
  570
  704|1971
  1346
  1324
  1287
  1251
  1216
  1147|1056
  863
  846
  821
  794
  768
  720|454
  424
  524
  620
  702
  780
  937|2996
  1999
  1971
  1927
  1884
  1841
  1759|1545
  1308
  1283
  1243
  1205
  1166
  1101| |50|0
  2
  5