CMC · California Mechanical Code
What installations are covered and what pressure limits apply?
For homeowners: The California Mechanical Code covers on‑site fuel gas piping from the meter/regulator outlet (the “point of delivery”) to the appliances — but only when the gas pressure is at or below **5 psi** for natural gas or **10 psi** for undiluted propane; check the point of delivery and pressure to know whether these chapter rules apply.
Last reviewed: July 6, 2026
What the code requires — 2–4 sentences
The California Mechanical Code (CMC) § 1301.1 says this chapter governs the installation of fuel gas piping in or connected with a building, structure or within the property lines of premises for pressures up to 5 psi (34 kPa) for natural gas and 10 psi (69 kPa) for undiluted propane, excluding service pipe. The CMC § 1302.1 defines the coverage of piping systems as extending from the point of delivery to the appliance connections and explains how the point of delivery is determined for different systems. Both provisions set the practical scope (what piping the chapter controls) and the pressure thresholds that keep an installation within this chapter’s requirements.
The single most important rule: the fuel gas piping rules in this chapter apply to on‑site piping from the system’s point of delivery to appliances — but only for gas pressures up to 5 psi for natural gas or 10 psi for undiluted propane; higher‑pressure systems fall outside this chapter.
Requirements in detail
Scope (which installations are covered)
- The chapter governs the installation of fuel gas piping in or in connection with a building, structure or within the property lines of premises where the supply pressure to the piping does not exceed the chapter thresholds — 5 psi (34 kPa) for natural gas and 10 psi (69 kPa) for undiluted propane. § 1301.1 is the controlling text for these limits.
Coverage (how far piping requirements extend)
- Coverage of piping systems extends from the point of delivery to the appliance connections. For most systems the point of delivery is the outlet of the service meter assembly or the outlet of the service regulator (or service shutoff where no meter is provided). For undiluted LP‑Gas systems the point of delivery is the outlet of the final pressure regulator (exclusive of line gas regulators) unless a meter is installed — then it’s the outlet of the meter. See § 1302.1 for the full definitions.
Table — decision‑relevant dimensions/values
| Installation element | Rule / Value | Code Reference |
|---|---|---|
| Maximum pressure governed for natural gas | 5 psi (34 kPa) (installation governed by chapter up to this pressure) | § 1301.1 |
| Maximum pressure governed for undiluted propane (LP‑Gas) | 10 psi (69 kPa) | § 1301.1 |
| Extent of coverage | From point of delivery to appliance connections | § 1302.1 |
| Definition — point of delivery (general systems) | Outlet of the service meter assembly or outlet of the service regulator (or service shutoff if no meter) | § 1302.1 |
| Definition — point of delivery (undiluted LP‑Gas) | Outlet of the final pressure regulator (unless a meter is installed — then outlet of the meter) | § 1302.1 |
What “other than service pipe” means in practice
- Service pipe (the utility’s service lateral up to the meter or service regulator) is not governed by the chapter’s installation rules described above — the chapter controls the piping downstream of the point of delivery as defined in § 1302.1. Confirm the local utility / authority having jurisdiction when in doubt.
Exceptions & special cases
- Portable LP‑Gas appliances and equipment that are not connected to a fixed fuel piping system are not covered by the chapter (see applicable exclusions). The chapter also excludes numerous industrial and specialized gas uses (see the CMC exceptions list). These exceptions are part of the broader applicability language connected to the piping coverage (see § 1302.3 in the same chapter).
- For undiluted LP‑Gas systems the point of delivery is the outlet of the final regulator (not the line regulator), so multiple regulators in series change where coverage begins — inspect regulator arrangement to determine coverage under § 1302.1.
- The chapter’s pressure thresholds are explicit; systems with supply pressures above 5 psi (natural gas) or 10 psi (undiluted propane) are not within these installation provisions and will require alternative code or standard compliance (the CMC text does not prescribe higher‑pressure coverage here).
Common mistakes
- Misidentifying the point of delivery: assuming the meter is always the point of delivery when an upstream final regulator is present for LP‑Gas. Check § 1302.1 for the correct point for LP‑Gas.
- Applying the chapter’s rules to utility service piping (service mains) instead of to piping downstream of the point of delivery; the chapter governs piping downstream of that point. Do not treat the utility’s service lateral as covered by these installation rules.
- Overlooking the pressure thresholds: installing or testing piping assuming the chapter covers higher pressures (above 5 psi natural gas / 10 psi undiluted propane) — those systems are outside the stated scope.
- Forgetting excluded applications (portable appliances, industrial gases, LNG, certain plant installations). Review the chapter exclusions before applying these rules.
Worked example
Scenario: A commercial kitchen receives natural gas from the utility. The meter outlet supplies building piping at 3 psi. The meter is located at the property line and there is a separate service regulator immediately after the meter that reduces pressure to 0.5 psi for the building appliance branch.
- Is the building piping covered by the chapter? Yes — the CMC governs fuel gas piping in or connected with the building for natural gas up to 5 psi; both the meter outlet and downstream piping to appliance connections are within the chapter’s scope because the supply pressure is ≤ 5 psi. Reference: § 1301.1 and § 1302.1.
- What is the point of delivery? For this system the point of delivery is the outlet of the service meter assembly (or outlet of the service regulator where no meter). Therefore the chapter’s coverage begins at that outlet and extends to appliance connections. Reference: § 1302.1.
- If the utility delivered 7 psi at the meter outlet instead: the supply pressure would exceed the 5 psi natural‑gas threshold; this installation would not be governed by the chapter provisions as stated in § 1301.1, and a different set of rules/standards would apply (the CMC text does not extend these specific installation rules above the stated pressure limit).
Related provisions
- § 1301.1 — Scope / applicability of fuel gas piping and the pressure thresholds (natural gas and undiluted propane).
- § 1302.1 — Coverage: point of delivery and extent of piping coverage to appliance connections.
- § 1302.2 — Piping system requirements (design, materials, testing, maintenance) — useful when determining what to do once an installation is within chapter scope.
- § 1302.3 — Applications excluded from this chapter (portable LP‑Gas, industrial gases, LNG, certain plants, etc.).
- § 1308.9 — Overpressure protection device requirements and setting (relevant when ensuring downstream appliances are not exposed to pressures above the chapter limits).
Code references
Grounded in the retrieved California Mechanical Code — click a citation to read the verbatim passage:
CMC § 1.11.0. High relevance — show source text
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 MECHANICAL CODE 273
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CHAPTER 13
FUEL GAS PIPING
1301.0 Scope of Gas Piping.
1301.1 Applicability. The regulations of this chapter shall govern the installation of fuel gas piping in or in connection with a building, structure or within the property lines of premises up to 5 pounds-force per square inch (psi) (34 kPa) for natural gas and 10 psi (69 kPa) for undiluted propane, other than service pipe.
1302.0 Coverage of Piping System.
1302.1 General. Coverage of piping systems shall extend from the point of delivery to the appliance connections. For other than undiluted liquefied petroleum gas (LP-Gas) systems, the point of delivery shall be the outlet of the service meter assembly or the outlet of the service regulator or service shutoff valve where no meter is provided. For undiluted LP-Gas systems, the point of delivery shall be considered to be the outlet of the final pressure regulator, exclusive of line gas regulators where no meter is installed. Where a meter is installed, the point of delivery shall be the outlet of the meter.
[NFPA 54:1.1.1.1(A)]
1302.2 Piping System Requirements. Requirements for piping systems shall include design, materials, components, fabrication, assembly, installation, testing, inspection, operation, and maintenance. [NFPA 54:1.1.1.1(E)]
1302.3 Applications. This chapter shall not apply to the following items:
(1) Portable LP-Gas appliances and equipment of all types that are not connected to a fixed fuel piping system.
(2) Installation of appliances such as brooders, dehydrators, dryers, and irrigation equipment used for agricultural
purposes.
(3) Raw material (feedstock) applications except for piping to special atmosphere generators.
(4) Oxygen-fuel gas cutting and welding systems.
(5) Industrial gas applications using such gases as acetylene and acetylenic compounds, hydrogen, ammonia, carbon monoxide, oxygen, and nitrogen.
(6) Petroleum refineries, pipeline compressor or pumping stations, loading terminals, compounding plants, refinery tank farms, and natural gas processing plants.
(7) Large integrated chemical plants or portions of such plants where flammable or combustible liquids or gases are produced by chemical reactions or used in chemical reactions.
(8) LP-Gas installations at utility gas plants.
(9) Liquefied natural gas (LNG) installations.
(10)Fuel gas piping in electric utility power plants.
(11)Proprietary items of equipment, apparatus, or instruments such as gas-generating sets, compressors, and calorime ters.
(12)LP-Gas equipment for vaporization, gas mixing, and gas manufacturing.
CMC § 904.9.3.1 High relevance — show source text
904.9.3.1 Test procedure. For Halon 1301 systems, hoses shall be tested at not less than 1,500 psi (10 343 kPa) for 600 psi (4137 kPa) charging pressure systems and not less than 900 psi (6206 kPa) for 360 psi (2482 kPa) charging pressure systems. For Halon 1211 hand-hose line systems, hoses shall be tested at 2,500 psi (17 238 kPa) for high-pressure systems and 900 psi (6206 kPa) for low-pressure systems.
904.9.4 Auxiliary equipment. Auxiliary and supplementary components, such as switches, door and window releases, interconnected valves, damper releases and supplementary alarms, shall be manually operated at 12-month intervals to ensure such components are in proper operating condition.
904.10 Clean-agent systems. Clean-agent fire-extinguishing systems shall be installed, maintained, periodically inspected and tested in accordance with California Code of Regulations, Title 19, Division 1, Chapter 5 and NFPA 2001 and their listing. Records of inspections and testing shall be maintained.
904.10.1 System test. Systems shall be inspected and tested for proper operation in accordance with California Code of Regula- tions, Title 19, Division 1, Chapter 5.
904.10.2 Containers. The extinguishing agent quantity and pressure of the containers shall be checked at six-month intervals. Where a container shows a loss in original weight of more than 5 percent or a loss in original pressure, adjusted for temperature, of more than 10 percent, the container shall be refilled or replaced. The weight and pressure of the container shall be recorded on a tag attached to the container.
904.10.3 System hoses. System hoses shall be examined at 12-month intervals for damage. Damaged hoses shall be replaced or tested. All hoses shall be tested at 5-year intervals.
904.11 Automatic water mist systems. Automatic water mist systems shall be permitted in applications that are consistent with the applicable listing or approvals and shall comply with Sections 904.11.1 through 904.11.3.
904.11.1 Design and installation requirements. Automatic water mist systems shall be designed and installed in accordance with Sections 904.11.1.1 through 904.11.1.4.
904.11.1.1 General. Automatic water mist systems shall be designed and installed in accordance with California Code of Regu- lations, Title 19, Division 1, Chapter 5 and NFPA 750 and the manufacturer’s instructions.
904.11.1.2 Actuation. Automatic water mist systems shall be automatically actuated.
904.11.1.3 Water supply protection. Connections to a potable water supply shall be protected against backflow in accordance with the California Plumbing Code .
904.11.1.4 Secondary water supply. Where a secondary water supply is required for an automatic sprinkler system, an automatic water mist system shall be provided with an approved secondary water supply.
904.11.2 Water mist system supervision and alarms. Supervision and alarms shall be provided as required for automatic sprinkler systems in accordance with Section 903.4.1.
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FIRE PROTECTION AND LIFE SAFETY SYSTEMS
CMC § 904.8.4.1 High relevance — show source text
904.8.4.1 Test procedure. Hoses shall be tested at not less than 2,500 pounds per square inch (psi) (17 238 kPa) for high-pressure systems and at not less than 900 psi (6206 kPa) for low-pressure systems.
904.8.5 Auxiliary equipment. Auxiliary and supplementary components, such as switches, door and window releases, interconnected valves, damper releases and supplementary alarms, shall be manually operated at 12-month intervals to ensure that such components are in proper operating condition.
904.9 Halon systems. Halogenated extinguishing systems shall be installed, maintained, periodically inspected and tested in accordance with California Code of Regulations, Title 19, Division 1, Chapter 5 and NFPA 12A and their listing. Records of inspections and testing shall be maintained.
904.9.1 System test. Systems shall be inspected and tested for proper operation in accordance with California Code of Regula- tions, Title 19, Division 1, Chapter 5.
904.9.2 Containers. The extinguishing agent quantity and pressure of containers shall be checked at six-month intervals. Where a container shows a loss in original weight of more than 5 percent or a loss in original pressure (adjusted for temperature) of more than 10 percent, the container shall be refilled or replaced. The weight and pressure of the container shall be recorded on a tag attached to the container.
904.9.3 System hoses. System hoses shall be examined at 12-month intervals for damage. Damaged hoses shall be replaced or tested. At five-year intervals, all hoses shall be tested.
904.9.3.1 Test procedure. For Halon 1301 systems, hoses shall be tested at not less than 1,500 psi (10 343 kPa) for 600 psi (4137 kPa) charging pressure systems and not less than 900 psi (6206 kPa) for 360 psi (2482 kPa) charging pressure systems. For Halon 1211 hand-hose line systems, hoses shall be tested at 2,500 psi (17 238 kPa) for high-pressure systems and 900 psi (6206 kPa) for low-pressure systems.
904.9.4 Auxiliary equipment. Auxiliary and supplementary components, such as switches, door and window releases, interconnected valves, damper releases and supplementary alarms, shall be manually operated at 12-month intervals to ensure such components are in proper operating condition.
904.10 Clean-agent systems. Clean-agent fire-extinguishing systems shall be installed, maintained, periodically inspected and tested in accordance with California Code of Regulations, Title 19, Division 1, Chapter 5 and NFPA 2001 and their listing. Records of inspections and testing shall be maintained.
904.10.1 System test. Systems shall be inspected and tested for proper operation in accordance with California Code of Regula- tions, Title 19, Division 1, Chapter 5.
904.10.2 Containers. The extinguishing agent quantity and pressure of the containers shall be checked at six-month intervals. Where a container shows a loss in original weight of more than 5 percent or a loss in original pressure, adjusted for temperature, of more than 10 percent, the container shall be refilled or replaced. The weight and pressure of the container shall be recorded on a tag attached to the container.
CMC § 92.9 High relevance — show source text
(3) 1000 square foot (92.9 m [2] ) heating surface
Power boilers that do not exceed one of the following limits:
(1) 5 000 000 Btu/h input (1464 kW)
(2) 5000 pounds steam per hour (0.6299 kg/s) capacity (3) 1000 square foot (92.9 m [2] ) heating surface
Boilers with manholes on top of the boiler, except those described in Section 1010.2 and Section 1010.4, shall have a clearance of not less than 3 feet (914 mm) from the top of the boiler to the ceiling. 1010.4 Package Boilers, Steam-Heating Boilers, and Hot-Water-Heating Boilers. Package boilers, steam-heating boilers, and hot-water-heating boilers with no manhole on top of the shell and not exceeding one of the above limits shall have a clearance of not less than 2 feet (610 mm) from the ceiling.
1011.0 Boilers, Stokers, and Steam Generators.
1011.1 General. The design, installation, and operation of single burner boilers, multiple burner boilers, stokers, and atmospheric fluidized-bed boilers with not less than a fuel input rating of 12.5 E+06 Btu/h (3.663 MW) to pulverized fuel systems, fired or unfired steam generators used to recover heat from combustion turbines and to other combustion turbine exhaust systems shall be in accordance with NFPA 85. That portion of the oil-burning system supplied on boilers and covered within the scope of NFPA 85 shall be installed in accordance with NFPA 85.
1012.0 Operating Adjustments and Instructions. 1012.1 General. Hot water boiler installations, upon completion, shall have controls set, adjusted, and tested by the installing contractor. A complete control diagram of a permanent legible type, together with complete boiler operating instructions, shall be furnished by the installer for each installation.
1013.0 Inspections and Tests. 1013.1 General. An installation for which a permit is required shall not be put into service until it has been inspected and approved by the Authority Having Jurisdiction.
It shall be the duty of the owner or his authorized representative to notify the Authority Having Jurisdiction that the installation is ready for inspection and test. It also shall be the duty of the owner or his authorized representative to post in a conspicuous position on the installation a notice in substantially the following form: “WARNING! THIS INSTALLATION HAS NOT BEEN INSPECTED AND APPROVED
BY THE AUTHORITY HAVING JURISDICTION AND
SHALL NOT BE COVERED OR CONCEALED UNTIL SO INSPECTED AND APPROVED,” and it shall be unlawful for anyone other than the Authority Having Jurisdiction to remove such notice. The Authority Having Jurisdiction shall require such tests as it deems necessary to determine that the installation is in accordance with the provision of this section. Such tests shall be made by the owner or his authorized representative in the presence of the Authority Having Jurisdiction.
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BOILERS AND PRESSURE VESSELS
CMC § 10-3 High relevance — show source text
1003 Building Elements and Materials . . . . . . . . . . . . . . . . 10-3
1004 Fire Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3
1005 Means of Egress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3
1006 Structural. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3
1007 Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4
1008 Mechanical. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4
1009 Plumbing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4
1010 Other Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5
1011 Change of Occupancy Classification . . . . . . . . . . . . . 10-5
CHAPTER 11 ADDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . .11-3
1101 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3
1102 Heights and Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3
1103 Structural. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4
1104 Energy Conservation. . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4
CHAPTER 12 HISTORIC BUILDINGS . . . . . . . . . . . . . . . . . .12-1
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CHAPTER 13 PERFORMANCE COMPLIANCE METHODS. . 13-3
1301 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-3
1302 Applicability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-3
1303 Acceptance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-4
CMC § 11-3 High relevance — show source text
1101 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3
1102 Heights and Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3
1103 Structural. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4
1104 Energy Conservation. . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4
CHAPTER 12 HISTORIC BUILDINGS . . . . . . . . . . . . . . . . . .12-1
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CHAPTER 13 PERFORMANCE COMPLIANCE METHODS. . 13-3
1301 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-3
1302 Applicability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-3
1303 Acceptance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-4
1304 Investigation and Evaluation . . . . . . . . . . . . . . . . . . . 13-4
1305 Scoring and Evaluation . . . . . . . . . . . . . . . . . . . . . . . . 13-4
1306 Building Score . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-14
1307 Evaluation of Building Safety. . . . . . . . . . . . . . . . . . 13-16
CHAPTER 14 RELOCATED OR MOVED BUILDINGS . . . . . . 14-3
1401 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-3
1402 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-3
CHAPTER 15 CONSTRUCTION SAFEGUARDS . . . . . . . . . . 15-3
1501 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-3
1502 Owner’s Responsibility for Fire Protection . . . . . . . 15-3
1503 Sanitary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-4
CMC § 510.4.2.4 Medium relevance — show source text
1, 510.4.2.4, 510.4.2.5, 510.5.2.1 Emergency Shutoff Valve 202, 5003.2.2.1, 5503.4.6, 5505.3.2, 6303.1.2, 6403.1.1 Emergency Shutoff Valve, Automatic 202, 2305.2.4, 2306.7.4, 5003.2.9.1, 5505.3.2, 5803.1.3, 6303.1.2, 6303.1.2.2, 6403.1.1.1 Emergency Shutoff Valve, Manual 202, 2309.5.2, 2309.5.2.1, 5505.3.2, 5803.1.3, 6303.1.2, 6303.1.2.2, 6403.1.1.2 Emergency Venting for Tanks 607.5, 2306.5, 5704.2.7.4, 5704.2.9.6.1.2, 5704.2.9.7.2 Emergency Voice/Alarm Communications 907.5.2.2
Atriums 907.2.14
Captions 907.5.2.2.4 Covered mall buildings 907.2.20 Deep underground buildings 907.2.19 Defined 202
Group A 907.2.1.1 High-rise building 907.2.13 Special amusement buildings 907.2.12.3 Employee Training 406 Employee Work Area Defined 202
Detached Building 202 Group H occupancies 5003.8.2 Storage 6204.1.1, Table 6204.1.2, 6304.1.1
Detector, Heat Defined 202 Detonating Cord Defined 202
Detonation
Defined 202
Detonator
Defined 202 Detoxification Facilities (Group I-2) 202, 203.7.2 Dip Tank 202, 2405 Permit 105.6.23 Dipping Operations 2405 Discharge, Exit (see Exit Discharge) Discharge of Hazardous Material (see Release of Hazardous Material) Dispensing Aircraft fueling 2006 Defined 202 Fire extinguishers 2305.5 Location 2303.1 Motor fuel-dispensing operations 2304
Requirements 2305, 5005 Dispensing Device, Overhead-Type Defined 202 Displays Aerosol products 5106 Cellulose nitrate (pyroxylin) plastic 314.3, 6503.1 Fireworks 5608
Group M 5003.11 Indoor 314
Motor vehicles 314.4, 3108.14 Retail 5001.4, 5106, 5601.2.2 Storage 5003.11.1.1 Distilled Spirits and Wines 4001 Fire protection 4005 Occupancy classification 203.10.3, 203.10.4, 203.5.1, 203.5.2 Precautions against fire 4003 Signage 4006 Storage 4004 Door 1010
CMC § 3.4.2 Medium relevance — show source text
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. Add 5 gpm to the flow rate required by Section_R309.3.4.2_ where the water service pipe supplies more than one dwelling.|TABLE R309.3.6.2(2)—MINIMUM WATER METER PRESSURE LOSS (PL )a
mCol2 Col3 Col4 FLOW RATE
(gallons per minute, gpm)b5/8-INCH METER PRESSURE LOSS
(pounds per square inch, psi)3/4-INCH METER PRESSURE LESS
(pounds per square inch, psi)1-INCH METER PRESSURE LOSS
(pounds per square inch, psi)8 3 3 1 10 3 3 1 12 4 3 1 14 6 5 1 16 7 6 1 18 9 7 2 20 11 9 2 23 14 11 3 26 18 14 3 31 26 22 4 39 38 35 6 52 NP NP 10 For SI: 1 inch = 25.4 mm, 1 pound per square inch = 6.895 kPa, 1 gallon per minute = 0.063 L/s.
NP = Not permitted unless the actual water meter pressure loss is known.
a. Table P2904.6.2(2) establishes conservative values for water meter pressure loss or installations where the water meter loss is unknown. Where the actual water meter pres-
sure loss is published and available from the meter manufacturer,PLm shall be the published pressure loss for the selected meter.
b.CMC § 1.11. Medium relevance — show source text
The 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.
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13 PERFORMANCE COMPLIANCE METHODS
Not adopted by the State of California (May be available for adoption by local ordinance. See Section 1.1.11.) (See Section 104.11 for consideration of alternative means of compliance.)
User notes:
About this chapter: Chapter 13 allows for existing buildings to be evaluated so as to show that alterations, while not meeting new construction requirements, will improve the current existing situation. Provisions are based on a numerical scoring system involving 21 various safety parameters and the degree of code compliance for each issue.
SECTION 1301—GENERAL
1301.1 Scope. The provisions of this chapter shall apply to the alteration, addition and change of occupancy of existing structures, including historic structures, as referenced in Section 301.3.3. The provisions of this chapter are intended to maintain or increase the current degree of public safety, health and general welfare in existing buildings while permitting, alteration, addition and change of occupancy without requiring full compliance with Chapters 6 through 12, except where compliance with the prescriptive method of Chapter 5 or the work area method of other provisions of this code is specifically required in this chapter.
1301.1.1 Compliance with other methods. Alterations, additions and changes of occupancy to existing structures shall comply with the provisions of this chapter or with one of the methods provided in Section 301.3.
SECTION 1302—APPLICABILITY
1302.1 General. Existing buildings in which there is work involving additions, alterations or changes of occupancy shall be made to conform to the requirements of this chapter or the provisions of Chapters 6 through 12. The provisions of Sections 1302.1.1 through 1302.1.6 shall apply to existing occupancies that will continue to be, or are proposed to be, in Groups A, B, E, F, I-2, M, R and S. These provisions shall also apply to Group U occupancies where such occupancies are undergoing a change of occupancy or a partial change in occupancy with separations in accordance with Section 1302.1.2. These provisions shall not apply to buildings with occupancies in Group H, I-1, I-3 or I-4.
1302.1.1 Change in occupancy. Where an existing building is changed to a new occupancy classification and this section is applicable, the provisions of this section for the new occupancy shall be used to determine compliance with this code.
1302.1.2 Partial change in occupancy. Where a portion of the building is changed to a new occupancy classification and that portion is separated from the remainder of the building with fire barrier or horizontal assemblies having a fire-resistance rating as required by Table 508.4 of the International Building Code or Section R302 of the International Residential Code for the separate occupancies, or with approved compliance alternatives, the portion changed shall be made to conform to the provisions of this section. Only the portion separated shall be required to be evaluated for compliance.
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
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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
APPLICATIONSTANDARDS
Appliance shutoff
valve up to1_/_2 psiCSA/ANSI Z21.15/CSA 9.1
Appliance shutoff
valve up to1_/_2 psiASME B16.44
Appliance shutoff
valve up to1_/_2 psiASME B16.33 marked 125 G
Appliance shutoff
valve up to1_/_2 psiCSA/ANSI LC 4/CSA 6.32
Valve up to1_/_2 psiASME B16.44
Valve up to1_/_2 psiASME B16.33 marked 125 G
Valve up to1_/_2 psiCSA/ANSI LC 4/CSA 6.32
Valve up to 2 psiASME B16.44 labeled 2G
Valve up to 2 psiASME B16.33 marked 125 G
Valve up to 2 psiCSA/ANSI LC 4/CSA 6. CMC § 03-25 Medium relevance — show source text
- If the desired connector size is not shown, special sizes may be acquired by ordering a connector similar to the connector shown.
Rev. #07: 03-25-22 015251 Page 31 of 39
UG-1: Connectors Greenbook Connectors for Insulated Cables Underground Distribution Systems
Tap Connectors for Cable Termination (copper or aluminum cable) Pad-Mounted Transformers (continued)
Transformer Terminal Rod
Pin Terminal
Transformer Terminal Rod
Figure 29
Figure 30 Blackburn Catalog Number PGH3, Code 305997
Application: Tap clamp for live-front loop-style, 3-phase pad-mounted transformer. Document 045291 and Document 057521 conductor range #2 AWG to 2/0.
Application
See “Low Profile” Single-Phase 6.9 and 12 kV pad-mounted transformer, Document 042762 and Document 042765.
Table 35 Tap Connectors for Cable Termination in “Low-Profile” Pad-Mounted Transformers (Figure 29)
Connector Size
AWG or kcmilManufacturer and Catalog Number 6-Ton Tool Dies # 1
12-TonTool Dies #
15-TonTool Dies #Connector
CodeConnector Size
AWG or kcmilKortick Kortick Kortick 4 Cu PMT-401 W4CRT
UCRT
UCRT2305057 2 Cu PMT-201 W2CRT
U2CRT
U2CRT2305058 2 Al PMTA-201 W2CART
U2CART
U2CART2305153 1/0 Al PMTA-1001 −
U25ART
U25ART2305264 1 Within this column, the first entry corresponds to a 6-ton press tool, the second entry corresponds to a 12-ton press tool, and the third entry corresponds to a 15-ton press tool. 2 A U-die adapter must be used when utilizing u-dies in a 15-ton press.
015251 Page 32 of 39 Rev. #07: 03-25-22
UG-1: Connectors Greenbook Connectors for Insulated Cables Underground Distribution Systems
Primary T-Connectors, Compression-Type,5 kV or Above Aluminum-to-Aluminum, Copper-to-Aluminum, or Copper-to-Copper
T (approx.)
CMC § 903.3.1.1 Medium relevance — show source text
Exception: The area limitation shall not apply where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or the building is equipped with smoke and heat vents in accordance with Section 910. 2610.5 Aggregate area of skylights. The aggregate area of skylights shall not exceed 33 [1] / 3 percent of the floor area of the room or space sheltered by the roof in which such skylights are installed where Class CC1 materials are utilized, and 25 percent where Class CC2 materials are utilized.
Exception: The aggregate area limitations of light-transmitting plastic skylights shall be increased 100 percent beyond the limitations set forth in this section where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or the building is equipped with smoke and heat vents in accordance with Section 910.
2610.6 Separation. Skylights shall be separated from each other by a distance of not less than 4 feet (1219 mm) measured in a horizontal plane.
Exceptions:
- Buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
- In Group R-3, multiple skylights located above the same room or space with a combined area not exceeding the limits set forth in Section 2610.4.
2610.7 Location. Where exterior wall openings are required to be protected in accordance with Section 705, a skylight shall not be installed within 6 feet (1829 mm) of such exterior wall.
2610.8 Combinations of roof panels and skylights. Combinations of light-transmitting plastic roof panels and skylights shall be subject to the area and percentage limitations and separation requirements applicable to roof panel installations.
SECTION 2611—LIGHT-TRANSMITTING PLASTIC INTERIOR SIGNS
2611.1 General. Light-transmitting plastic interior signs shall be limited as specified in Sections 2606 and 2611.2 through 2611.4.
Exception: Light-transmitting plastic interior wall signs in covered and open mall buildings shall comply with Section 402.6.4. 2611.2 Maximum area. The aggregate area of all light-transmitting plastics shall not exceed 24 square feet (2.23 m [2] ).
Exception: In buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1, the aggregate area of light-transmitting plastics shall not exceed 100 square feet (9.29 m [2] ), provided that all plastics are Class CC1 in accordance with Section 2606.4.
2025 CALIFORNIA BUILDING CODE 26-11
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
PLASTIC
2611.3 Separation. Signs exceeding the aggregate area of Section 2611.2 shall be separated from each other by not less than 4 feet (1219 mm) horizontally and 8 feet (2438 mm) vertically.
2611.4 Encasement. Backs of wall-mounted signs and non-illuminated portions of all signs regulated by this section shall be fully encased in metal.
SECTION 2612—PLASTIC COMPOSITE DECKING
Frequently asked questions
Who decides whether a system is “within” the chapter — the AHJ or the installer?
The Authority Having Jurisdiction (AHJ) makes the official determination, but installers must identify the point of delivery and confirm the supply pressure against the chapter thresholds (§ 1301.1 and § 1302.1) when preparing plans and installations.
If the building has multiple regulators in series, where does coverage start?
For typical (non‑LP) systems coverage starts at the outlet of the meter or service regulator; for undiluted LP‑Gas the point of delivery is the outlet of the final pressure regulator (unless a meter is installed) — see § 1302.1.
Does the chapter apply to service piping (utility lateral) on the street?
No — the chapter’s installation rules apply other than service pipe; the piping governed by the chapter begins at the defined point of delivery (meter or regulator outlet). § 1301.1 and § 1302.1 explain these distinctions.
Are higher‑pressure gas systems (over 5 psi natural gas) addressed here?
No. The chapter explicitly governs installations up to 5 psi for natural gas and 10 psi for undiluted propane. Systems with higher supply pressures are not covered by these specific provisions in § 1301.1.
Where can I find the list of installations that are excluded from the chapter?
See § 1302.3 for the chapter’s list of excluded applications (portable LP appliances, industrial gas systems, LNG, certain plant installations, etc.).
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