CMC · California Mechanical Code
When is a permit required for process piping?
If you are going to install, change, or repair any process piping, you must obtain a permit first and list the total number of outlets on the application; the local building department (AHJ) can require plans and will set fees per the CMC’s fee structure. **§ 1402.1**. file
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
The California Mechanical Code makes it unlawful to install, alter, or repair process material piping without first obtaining a permit — see § 1402.1. Permits must show the total number of outlets for each system and any other information required by the Authority Having Jurisdiction (AHJ); permit fees for process piping are defined in Table 104.5.
The single most important rule: you must obtain a permit before you install, alter, or repair any process piping system, and your permit application must list how many outlets the system will serve. § 1402.1
Requirements in detail
Core trigger — what actions require a permit
- Any attempt to install, alter, or repair process material piping requires a permit. § 1402.1
- The permit application must show the total number of outlets for each system and include other information the AHJ requires. § 1402.1
What you must provide with the permit (what the code authorizes the AHJ to require)
- The code expressly permits the AHJ to require plans, engineering calculations, diagrams, and other data with each permit application (see § 1403.1).
- Where plans are submitted, a plan review fee may apply per the fee provisions (see Table 104.5 and Section 104.3.2).
Inspections and testing tied to the permit
- Once work is complete, the AHJ must be notified for inspection before the piping is put into service; required inspections include rough and final piping inspections and pressure testing as specified in § 1405.1 and § 1405.2.
Decision-relevant dimensions at a glance
| Decision dimension | Trigger / Value | What the code requires you to do | Code Reference |
|---|---|---|---|
| Work type | Install, alter, or repair | Obtain a permit before work begins | § 1402.1 |
| System information | Total number of outlets | Show total outlets on permit application; AHJ may require additional detail | § 1402.1 |
| Fees | 1–4 outlets vs 5 or more outlets | Fee structure distinguishes 1–4 outlets and 5+ outlets (per outlet) for HPP and NPP — jurisdiction fills amounts in Table 104.5 | Table 104.5 / § 104.5 (see process piping entries) |
| Plans | Any permit application | AHJ may require plans, engineering calculations, diagrams | § 1403.1 |
| Inspections | After installation / before use | Notify AHJ for rough and final inspections and pressure tests | § 1405.1, § 1405.2 |
| Material & standard | Process piping materials | Must comply with ASME B31.3 and be suitable for operating conditions | § 1406.1 |
Exceptions & special cases
- The CMC text for § 1402.1 does not list specific permit exceptions for process piping; it states the general requirement to obtain a permit and that permits must show outlets and other information as required by the AHJ. § 1402.1
- Local jurisdictions often adopt administrative exceptions (for example, emergency repairs or minor repairs) in other parts of law or local regulations; those are not specified in § 1402.1 and would be set by the AHJ. The code allows the AHJ to set submittal requirements (plans, fees, etc.).
- Process piping that also falls under other chapters (fuel-gas piping, refrigeration, hydronics, etc.) may need to comply with Chapter 14 in addition to the applicable chapter for those systems. The chapter introduction describes that Chapter 14 governs piping used directly in research, laboratory, or production processes and may be used alongside other chapters as appropriate.
If you need a definitive answer about local exceptions (for example whether a specific small repair in your city needs a permit), contact the AHJ because § 1402.1 delegates some submission details to that authority.
Common mistakes
- Assuming no permit is needed for “small” process piping changes — the code’s trigger is the work type (install/alter/repair), not the dollar value or perceived size; § 1402.1 requires a permit.
- Forgetting to list the total number of outlets on the permit application — the code explicitly requires this information. § 1402.1
- Using only fuel-gas chapter rules for piping that is process piping in nature — Chapter 14 applies where the piping is used directly in process/research/production even if gas or refrigerant is involved (Chapter 13, 11, etc. may also apply).
- Relying on a single inspection (no rough inspection) — the CMC lists required rough and final inspections and pressure testing tied to permit work. § 1405.2
- Assuming Table 104.5 fee amounts are statewide-fixed dollar numbers — Table 104.5 shows the fee structure (1–4 vs 5+ outlets) but the actual fee values are set by the jurisdiction.
Worked example — concrete scenario
Scenario: A laboratory installs a hazardous process piping (HPP) supply system that will serve 6 outlets.
Step 1 — Permit required:
- Because the work is an installation of process piping, a permit is required before beginning work. § 1402.1
Step 2 — Application content:
- The permit application must show the total number of outlets = 6 and any other information the AHJ requires (plans, diagrams, etc.). § 1402.1; § 1403.1 for plans.
Step 3 — Fees (how the code structures fees):
- Table 104.5 splits process piping fees into HPP of 1–4 outlets and HPP of 5 or more outlets (per outlet). The actual dollar amounts are jurisdictional; calculate the fee as: base fee for an HPP system of 1–4 outlets + per-outlet fee for each outlet beyond 4 (i.e., outlets 5 and 6). See Table 104.5 for the AHJ’s fee values.
Step 4 — Inspections and testing:
- Schedule rough and final inspections and be prepared to perform pressure tests per the inspection provisions once installed. § 1405.1, § 1405.2.
Related provisions
- § 1401.1 — Applicability (scope of Chapter 14)
- § 1403.1 — Plans required with permit applications (plans, calculations, etc.)
- § 1405.1 / § 1405.2 — Inspection requirements (rough, final, testing)
- § 1406.1 — Pipe, tubing, and fittings must comply with ASME B31.3 and be suitable for service conditions
- Table 104.5 — Mechanical permit fee structure for process piping (HPP and NPP; 1–4 outlets vs 5+ outlets)
Code references
Grounded in the retrieved California Mechanical Code — click a citation to read the verbatim passage:
CMC § 1401.0 High relevance — show source text
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CHAPTER 14
PROCESS PIPING
1401.0 General.
1401.1 Applicability. Except as otherwise addressed in this code, this chapter shall govern the installation of process piping in or in conjunction with a building or structure located upon the premises.
1402.0 Permit.
1402.1 General. It shall be unlawful to install, alter, or repair or cause to be installed, altered, or repaired process material piping without first obtaining a permit.
Permits for process piping shall show the total number of outlets to be provided for on each system and such other information as required by the Authority Having Jurisdiction.
Fees for process piping permits are included in Table 104.5.
1403.0 Plans Required.
1403.1 General. Plans, engineering calculations, diagrams, and other data shall be submitted in one or more sets with each application for a permit. The Authority Having Jurisdiction shall be permitted to require plans, computations, and specifications to be prepared and designed by a registered design professional.
Where plans or other data are submitted for review, a plan review fee shall be paid, as provided in Section 104.3.2.
1404.0 Workmanship.
1404.1 General. Process piping shall not be strained or bent, nor shall tanks, vessels, vats, appliances, or cabinets be supported by or develop strain or stress on the piping.
1405.0 Inspections.
1405.1 General. Upon completion of the installation, alteration, or repair of process piping, and prior to the use thereof, the Authority Having Jurisdiction shall be notified that such piping is ready for inspection.
Excavations required for the installation of underground piping shall be kept open until such time as the piping has been inspected and approved. Where such piping is covered or concealed before such approval, it shall be exposed upon the direction of the Authority Having Jurisdiction.
1405.2 Required Inspections. The Authority Having Jurisdiction shall make the following inspections and shall either approve that portion of the work as completed or shall notify the permit holder wherein the same fails to be in accordance with this code.
1405.2.1 Rough Piping Inspection. This inspection shall be made after process piping authorized by the permit has been installed and before piping has been cov
ered or concealed. This inspection shall include a determination that the piping size, material, and installation are in accordance with the requirements of this code.
1405.2.2 Final Piping Inspection. This inspection shall be made after piping authorized by the permit has been installed and after portions thereof that are to be covered or concealed are so concealed. This inspection shall include a pressure test, at which time the piping shall stand a pressure of not less than one-and-one-half times the maximum designed operating pressure where hydraulic testing is conducted or 110 percent where testing is conducted pneumatically. Test pressures shall be held for a length of time satisfactory to the Authority Having Jurisdiction, but in no case for less than 30 minutes with no perceptible drop in pressure. HPM drain, waste, and vent piping shall be tested in accordance with the plumbing code. Tests shall be made in the presence of the Authority Having Jurisdiction. Necessary apparatus for conducting tests shall be furnished by the permit holder.
CMC § 1.11.0. High relevance — show source text
SS/CC**|1|1R|2|3|4|5|6|6|6|6|6|6|6|6|6| |Adopting Agency
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amended (amended sections
listed below)
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amended (amended sections
listed below)
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that are listed below
Chapter/Section||||||||||||||||||||||||| |Adopting Agency
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amended (amended sections
listed below)
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Chapter/Section|||||||||||||||||||||||||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.
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334 2025 CALIFORNIA MECHANICAL CODE
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CHAPTER 14
PROCESS PIPING
1401.0 General.
1401.1 Applicability. Except as otherwise addressed in this code, this chapter shall govern the installation of process piping in or in conjunction with a building or structure located upon the premises.
1402.0 Permit.
1402.1 General. It shall be unlawful to install, alter, or repair or cause to be installed, altered, or repaired process material piping without first obtaining a permit.
Permits for process piping shall show the total number of outlets to be provided for on each system and such other information as required by the Authority Having Jurisdiction.
Fees for process piping permits are included in Table 104.5.
1403.0 Plans Required.
1403.1 General. Plans, engineering calculations, diagrams, and other data shall be submitted in one or more sets with each application for a permit. The Authority Having Jurisdiction shall be permitted to require plans, computations, and specifications to be prepared and designed by a registered design professional.
Where plans or other data are submitted for review, a plan review fee shall be paid, as provided in Section 104.3.2.
1404.0 Workmanship.
1404.1 General. Process piping shall not be strained or bent, nor shall tanks, vessels, vats, appliances, or cabinets be supported by or develop strain or stress on the piping.
CMC § 1405.2 Medium relevance — show source text
Excavations required for the installation of underground piping shall be kept open until such time as the piping has been inspected and approved. Where such piping is covered or concealed before such approval, it shall be exposed upon the direction of the Authority Having Jurisdiction.
1405.2 Required Inspections. The Authority Having Jurisdiction shall make the following inspections and shall either approve that portion of the work as completed or shall notify the permit holder wherein the same fails to be in accordance with this code.
1405.2.1 Rough Piping Inspection. This inspection shall be made after process piping authorized by the permit has been installed and before piping has been cov
ered or concealed. This inspection shall include a determination that the piping size, material, and installation are in accordance with the requirements of this code.
1405.2.2 Final Piping Inspection. This inspection shall be made after piping authorized by the permit has been installed and after portions thereof that are to be covered or concealed are so concealed. This inspection shall include a pressure test, at which time the piping shall stand a pressure of not less than one-and-one-half times the maximum designed operating pressure where hydraulic testing is conducted or 110 percent where testing is conducted pneumatically. Test pressures shall be held for a length of time satisfactory to the Authority Having Jurisdiction, but in no case for less than 30 minutes with no perceptible drop in pressure. HPM drain, waste, and vent piping shall be tested in accordance with the plumbing code. Tests shall be made in the presence of the Authority Having Jurisdiction. Necessary apparatus for conducting tests shall be furnished by the permit holder.
1405.3 Other Inspections. In addition to the inspections required by this section, the Authority Having Jurisdiction shall be permitted to require a special inspector, as specified in the building code, during installation of piping systems. In cases where the work authorized was installed in accordance with plans and specifications prepared by a registered design professional, the Authority Having Jurisdiction shall be permitted to require a final signed report stating that the work was installed in accordance with approved plans and specifications and the applicable provisions of this chapter.
1406.0 Pipe, Tubing, and Fittings.
1406.1 General. Process pipe, tubing, and fittings shall comply with ASME B31.3 and shall be installed in accordance with the manufacturer’s installation instructions. Materials shall be rated for the operating temperatures and pressures of the system, and shall be compatible with the type of liquid.
1406.2 Hazardous Process Piping (HPP). HPP supply piping or tubing in service corridors shall be exposed to view. HPP piping shall be identified in accordance with nationally recognized standards to indicate the material being transported. Liquid HPP piping shall have an approved means for directing spilled materials to an approved containment or drainage system.
Liquid HPP waste or drainage systems shall be installed in accordance with the plumbing code.
1406.2.1 Installation in Exit Corridors and Above Other Occupancies. Hazardous process supply pipe shall not be located within exit corridors, within a portion of a means of egress required to be enclosed in fire-resistive construction, or in concealed spaces in or above
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PROCESS PIPING
areas not classified as Group H Occupancies, except as permitted by this subsection.
CMC § 104.5 Medium relevance — show source text
- Boilers, Compressors, and Absorption Systems:
For the installation or relocation of each boiler or compressor, not exceeding 3 horsepower (hp), or each absorption system not exceeding 100 000 Btu/h......................................................_____ [1 ]
For the installation or relocation of each boiler or compressor exceeding 3 hp, not exceeding 15 hp, or each absorption system exceeding 100 000 Btu/h and including 500 000 Btu/h ................................._____ [1 ]
For the installation or relocation of each boiler or compressor exceeding 15 hp, not exceeding 30 hp, or each absorption system exceeding 500 000 Btu/h, not exceeding 1 000 000 Btu/h............................._____ [1 ]
For the installation or relocation of each boiler or compressor exceeding 30 hp, not exceeding 50 hp, or for each absorption system exceeding 1 000 000 Btu/h, not exceeding 1 750 000 Btu/h............................................................................................................................._____ [1] For the installation or relocation of each boiler or compressor exceeding 50 hp, or each absorption system exceeding 1 750 000 Btu/h........................................................................................_____ [1]
- Air Handlers:
For each air-handling unit not exceeding 10 000 cubic feet per minute (CFM), including ducts attached thereto........................................................................................................................_____ [1, 2]
- Evaporative Coolers: For each air-handling unit exceeding 10 000 CFM ............................................................................................._____ [1 ]
For each evaporative cooler other than portable type .........................................................................................._____ [1]
- Ventilation and Exhaust: For each ventilation fan connected to a single duct ............................................................................................._____ [1 ]
For each ventilation system that is not a portion of a heating or air-conditioning system authorized by a permit.........................................................................................................................................._____ [1]
For the installation of each hood that is served by mechanical exhaust, including the ducts for such hood ........................................................................................................................_____ [1]
- Incinerators:
For the installation or relocation of each domestic-type incinerator...................................................................._____ [1] For the installation or relocation of each commercial or industrial-type incinerator..........................................._____ [1]
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DIVISION II SCOPE AND ADMINISTRATION
TABLE 104.5 (continued)
MECHANICAL PERMIT FEES
- Miscellaneous:
For each appliance or piece of equipment regulated by this code, but not classed in other appliance categories, or for which no other fee is listed in this table..................................................................................._____ [1]
- Fuel Gas Piping:
Where Chapter 13 or Appendix B is applicable (See Section 101.2), permit fees for fuel-gas piping shall be as follows: For each gas piping system of one to five outlets ................................................................................................_____ [1] For each additional gas piping system, per outlet................................................................................................_____ [1]
- Process Piping: For each hazardous process piping system (HPP) of one to four outlets............................................................._____ [1]
CMC § 1315.2 Medium relevance — show source text
Table 1315.2(27) Schedule 40 Metallic Pipe . . . . . . 322
Table 1315.2(28) Semi-Rigid Copper Tubing . . . . . . 323
Table 1315.2(29) Semi-Rigid Copper Tubing . . . . . . 324
Table 1315.2(30) Semi-Rigid Copper Tubing . . . . . . 330
Table 1315.2(31) Corrugated Stainless Steel Tubing (CSST) . . . . . . . . . . . . . . . 326
Table 1315.2(32) Corrugated Stainless Steel Tubing (CSST) . . . . . . . . . . . . . . . 327
Table 1315.2(33) Corrugated Stainless Steel Tubing (CSST) . . . . . . . . . . . . . . . 328
Table 1315.2(34) Polyethylene Plastic Pipe . . . . . . . 329
Table 1315.2(35) Polyethylene Plastic Pipe . . . . . . . 330
Table 1315.2(36) Polyethylene Plastic Tubing . . . . . 331
CHAPTER 14 PROCESS PIPING. . . . . . . . . . . . 333
1401.0 General. . . . . . . . . . . . . . . . . . . . . 335
1401.1 Applicability. . . . . . . . . . . . . . . . . . 335
1402.0 Permit . . . . . . . . . . . . . . . . . . . . . . 335
1402.1 General. . . . . . . . . . . . . . . . . . . . . 335
1403.0 Plans Required . . . . . . . . . . . . . . . 335
1403.1 General. . . . . . . . . . . . . . . . . . . . . 335
1404.0 Workmanship . . . . . . . . . . . . . . . . 335
1404.1 General. . . . . . . . . . . . . . . . . . . . . 335
1405.0 Inspections . . . . . . . . . . . . . . . . . . 335
1405.1 General. . . . . . . . . . . . . . . . . . . . . 335
1405.2 Required Inspections . . . . . . . . . . 335
1405.3 Other Inspections . . . . . . . . . . . . . 335
1406.0 Pipe, Tubing, and Fittings. . . . . . . 335
1406.1 General. . . . . . . . . . . . . . . . . . . . . 335
1406.2 Hazardous Process
Piping (HPP). . . . . . . . . . . . . . . . . 335
1406.3 Special Requirements for HPP Gases . . . . . . . . . . . . . . . . . . . . . . 336
CHAPTER 15 SOLAR ENERGY SYSTEMS. . . . 337
CMC § 4.54 Medium relevance — show source text
Mechanical:
- Portable heating appliances.
- Portable ventilation appliances.
- Portable cooling units.
- Steam, hot- or chilled-water piping within any heating or cooling equipment regulated by this code.
- Replacement of any minor part that does not alter approval of equipment or make such equipment unsafe.
- Portable evaporative coolers.
- Self-contained refrigeration systems containing 10 pounds (4.54 kg) or less of refrigerant or that are actuated by motors of 1 horsepower (746 W) or less.
- Portable-fuel-cell appliances that are not connected to a fixed piping system and are not interconnected to a power grid.
Plumbing:
The stopping of leaks in drains, water, soil, waste or vent pipe; provided, however, that if any concealed trap, drainpipe, water, soil, waste or vent pipe becomes defective and it becomes necessary to remove and replace the same with new material, such work shall be considered as new work and a permit shall be obtained and inspection made as provided in this code.
The clearing of stoppages or the repairing of leaks in pipes, valves or fixtures, and the removal and reinstallation of water closets, provided such repairs do not involve or require the replacement or rearrangement of valves, pipes or fixtures.
R105.2.1 Emergency repairs. Where equipment replacements and repairs must be performed in an emergency situation, the permit application shall be submitted within the next working business day to the building official.
R105.2.2 Repairs. Application or notice to the building official is not required for ordinary repairs to structures, replacement of lamps or the connection of approved portable electrical equipment to approved permanently installed receptacles. Such repairs shall not include the cutting away of any wall, partition or portion thereof, the removal or cutting of any structural beam or loadbearing support, or the removal or change of any required means of egress, or rearrangement of parts of a structure affecting the egress requirements; nor shall ordinary repairs include addition to, alteration of, replacement or relocation of any water supply, sewer, drainage, drain leader, gas, soil, waste, vent or similar piping, electric wiring or mechanical or other work affecting public health or general safety.
R105.2.3 Public service agencies. A permit shall not be required for the installation, alteration or repair of generation, transmission, distribution, metering or other related equipment that is under the ownership and control of public service agencies by established right.
R105.3 Application for permit. To obtain a permit, the applicant shall first file an application therefor in writing on a form furnished by the department of building safety for that purpose. Such application shall:
- Identify and describe the work to be covered by the permit for which application is made.
- Describe the land on which the proposed work is to be done by legal description, street address or similar description that will readily identify and definitely locate the proposed building or work.
- Indicate the use and occupancy for which the proposed work is intended.
- Be accompanied by construction documents and other information as required in Section R106.1.
- State the valuation of the proposed work.
- Be signed by the applicant or the applicant’s authorized agent.
- Give such other data and information as required by the building official.
CMC § 104.5 Medium relevance — show source text
For each ventilation system that is not a portion of a heating or air-conditioning system authorized by a permit.........................................................................................................................................._____ [1]
For the installation of each hood that is served by mechanical exhaust, including the ducts for such hood ........................................................................................................................_____ [1]
- Incinerators:
For the installation or relocation of each domestic-type incinerator...................................................................._____ [1] For the installation or relocation of each commercial or industrial-type incinerator..........................................._____ [1]
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DIVISION II SCOPE AND ADMINISTRATION
TABLE 104.5 (continued)
MECHANICAL PERMIT FEES
- Miscellaneous:
For each appliance or piece of equipment regulated by this code, but not classed in other appliance categories, or for which no other fee is listed in this table..................................................................................._____ [1]
- Fuel Gas Piping:
Where Chapter 13 or Appendix B is applicable (See Section 101.2), permit fees for fuel-gas piping shall be as follows: For each gas piping system of one to five outlets ................................................................................................_____ [1] For each additional gas piping system, per outlet................................................................................................_____ [1]
- Process Piping: For each hazardous process piping system (HPP) of one to four outlets............................................................._____ [1] For each HPP piping system of five or more outlets, per outlet .........................................................................._____ [1] For each nonhazardous process piping system (NPP) of one to four outlets......................................................._____ [1] For each NPP piping system of five or more outlets, per outlet .........................................................................._____ [1]
Other Inspections and Fees
Inspections outside of normal business hours, per hour (minimum charge – 2 hours)..............................................._____ [1]
Reinspection fees assessed under provisions of Section 105.2.6, per inspection ......................................................._____ [1]
Inspections for which no fee is specifically indicated, per hour (minimum charge – [1] ∕ 2 hour)..................................._____ [1]
Additional plan review required by changes, additions, or revisions to plans or to plans for which an initial review has been completed, per hour (minimum charge – [1] ∕ 2 hour).................................................................._____ [1]
For SI units: 1000 British thermal units per hour = 0.293 kW, 1 horsepower = 0.746 kW, 1 cubic foot per minute = 0.00047 m [3] / s
Notes:
1 Jurisdiction will indicate their fees here.
2 This fee shall not apply to an air-handling unit that is a portion of a factory-assembled appliance, cooling unit, evaporative cooler, or absorption unit for which a permit is required elsewhere in this code.
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CALIFORNIA MECHANICAL CODE – MATRIX ADOPTION TABLE
CHAPTER 2 – DEFINITIONS
(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.)
CMC § 1.1.1.2 Medium relevance — show source text
(14)Installation of LP-Gas systems for railroad switch heating.
(15)Installation of LP-Gas and compressed natural gas (CNG) systems on vehicles.
(16)Gas piping, meters, gas pressure regulators, and other appurtenances used by the serving gas supplier in distribution of gas, other than undiluted LP-Gas.
(17)Building design and construction, except as specified herein.
(18)Fuel gas systems on recreational vehicles manufactured in accordance with NFPA 1192.
(19)Fuel gas systems using hydrogen as a fuel.
(20)Construction of appliances. {NFPA 54:1.1.1.2}
1303.0 Inspection. 1303.1 Inspection Notification. Upon completion of the installation, alteration, or repair of gas piping, and prior to the use thereof, the Authority Having Jurisdiction shall be notified that such gas piping is ready for inspection. 1303.2 Excavation. Excavations required for the installation of underground piping shall be kept open until such time as the piping has been inspected and approved. Where such piping is covered or concealed before such approval, it shall be exposed upon the direction of the Authority Having Jurisdiction.
1303.3 Type of Inspections. The Authority Having Jurisdiction shall make the following inspections and either shall approve that portion of the work as completed or shall notify the permit holder wherein the same fails to be in accordance with this code.
1303.3.1 Rough Piping Inspection. This inspection shall be made after gas piping authorized by the permit has been installed before such piping has been covered or concealed, or before fixture or appliance has been attached thereto. This inspection shall include a determination that the gas piping size, material, and installation meet the requirements of this code. 1303.3.2 Final Piping Inspection. This inspection shall be made after piping authorized by the permit has been installed and after portions thereof that are to be covered or concealed are so concealed and before fixture, appliance, or shutoff valve has been attached thereto. This inspection shall comply with Section 1313.1. Test gauges used in conducting tests shall be in accordance with Section 1303.3.3 through Section 1303.3.3.4.
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FUEL GAS PIPING
1303.3.3 Test Gauges. Tests required by this code, which are performed utilizing dial gauges, shall be limited to gauges having the following pressure graduations or increments.
1303.3.3.1 Pressure Tests (10 psi or less). Required pressure tests of 10 psi (69 kPa) or less shall be performed with gauges of 0.10 psi (0.69 kPa) increments or less.
1303.3.3.2 Pressure Tests (greater than 10 psi to 100 psi). Required pressure tests exceeding 10 psi (69 kPa) but less than or equal to 100 psi (689 kPa) shall be performed with gauges of 1 psi (7 kPa) increments or less.
1303.3.3.3 Pressure Tests (exceeding 100 psi). Required pressure tests exceeding 100 psi (689 kPa) shall be performed with gauges of 2 percent increments or less of the required test pressure.
CMC § 1303.3.3.1 Medium relevance — show source text
Necessary apparatus for conducting tests shall be furnished by the permit holder. Test gauges used in conducting test shall be in accordance with Section 1303.3.3.1 through Section 1303.3.3.4. 1313.4 Detection of Leaks and Defects. The piping system shall withstand the test pressure specified without showing any evidence of leakage or other defects. Any reduction of test pressures as indicated by pressure gauges shall be deemed to indicate the presence of a leak unless such reduction can be readily attributed to some other cause. [NFPA 54:8.1.5.1] 1313.4.1 Detecting Leaks. The leakage shall be located by means of an approved gas detector, a noncorrosive leak detection fluid, or other approved leak detection methods. [NFPA 54:8.1.5.2] 1313.4.2 Repair or Replace. Where leakage or other defects are located, the affected portion of the piping system shall be repaired or replaced and retested. [NFPA 54:8.1.5.3] 1313.5 Piping System Leak Test. Leak checks using fuel gas shall be permitted in piping systems that have been pressure-tested in accordance with Section 1313.0 through Section 1313.4.2. [NFPA 54:8.2.1] 1313.5.1 Turning Gas On. During the process of turning gas on into a system of new gas piping, the entire system shall be inspected to determine that there are no open fittings or ends and that all valves at unused outlets are closed and plugged or capped. [NFPA 54:8.2.2] 1313.5.2 Leak Check. Immediately after the gas is turned on into a new system or into a system that has been initially restored after an interruption of service, the piping system shall be checked for leakage. Where leakage is indicated, the gas supply shall be shut off until the necessary repairs have been made. [NFPA 54:8.2.3]
1313.5.3 Placing Appliances and Equipment in Operation. Appliances and equipment shall not be placed in operation until after the piping system has been checked for leakage in accordance with Section 1313.5.2, the piping system is purged in accordance with Section 1313.6, and connections to the appliance are checked for leakage. [NFPA 54:8.2.4]
1313.6 Purging Requirements. The purging of piping shall be in accordance with Section 1313.6.1 through Section 1313.6.3. [NFPA 54:8.3]
1313.6.1 Piping Systems Required to be Purged Outdoors. The purging of piping systems shall be in accordance with Section 1313.6.1.1 through Section 1313.6.1.4 where the piping system meets either of the following:
(1) The design operating gas pressure is greater than 2 psig (14 kPag).
(2) The piping being purged contains one or more sections of pipe or tubing meeting the size and length criteria of Table 1313.6.1. [NFPA 54:8.3.1]
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CMC § 0.34 Medium relevance — show source text
32 to 0.34|250|4.5|5.0|5.0|5.0|5.0| |251 to 350|0.29 to 0.32|200|3.0|4.0|4.5|4.5|4.5| |201 to 250|0.27 to 0.30|150|2.5|2.5|2.5|3.0|3.0| |141 to 200|0.25 to 0.29|125|1.5|1.5|2.0|2.0|2.0| |105 to 140|0.22 to 0.28|100|1.0|1.0|1.5|1.5|1.5|
For SI units: °C=(°F-32)/1.8, 1 inch = 25 mm, 1 British thermal unit inch per hour square foot degree Fahrenheit = [0.1 W/(m•K)]
Notes: 1 For insulation outside the stated conductivity range, the minimum thickness ( T ) shall be determined as follows: T = r {(1 + t / r ) [K] [/] [k ] – 1}
Where:
T = minimum insulation thickness (inches). r = actual outside radius of pipe (inches). t = insulation thickness listed in this table for applicable fluid temperature and pipe size. K = conductivity of alternate material at mean rating temperature indicated for the applicable fluid temperature [Btu•in/(h•ft [2] - °F)] [W/(m•K)]. k = the upper value of the conductivity range listed in this table for the applicable fluid temperature. 2 These thicknesses are on energy efficiency considerations only. Additional insulation is sometimes required relative to safety issues/surface temperature. 3 For piping smaller than 1 1 ⁄ 2 inches (40 mm) or less and located in partitions within conditioned spaces, reduction of these thicknesses by 1 inch (25.4 mm) shall be permitted (before thickness adjustment required in footnote 1) but not to thicknesses below 1 inch (25.4 mm). 4 For direct-buried heating and hot water system piping, reduction of these thicknesses by 1 1 ⁄ 2 inch (40 mm) shall be permitted (before thickness adjustment required in footnote 1) but not to thicknesses below 1 inch (25.4 mm). 5 Table E 503.7.3(1) is based on steel pipe. Nonmetallic pipes schedule 80 thickness or less shall use the table values. For other nonmetallic pipes having thermal resistance more than that of steel pipe, reduced insulation thicknesses are permitted where documentation is provided showing that the pipe with the proposed insulation has no more heat transfer per foot (mm) than a steel pipe of the same size with the insulation thickness shown in Table E 503.7.3(1).
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APPENDIX E
TABLE E 503.7.3(2) MINIMUM PIPE INSULATION THICKNESS FOR COOLING SYSTEMS (CHILLED WATER, BRINE, AND REFRIGERANT) [1,2,3,4 ]
[ASHRAE 90.1: TABLE 6.8.3-2]
CMC § 1102.3 Medium relevance — show source text
A major milestone reached in the industry was the introduction of lower flammability refrigerants such as A2L and B2L. The industry’s concerns to address lower Global Warming Potential (GWP) refrigerants led to the development of these lower flammability refrigerants. Chapter 11 does not only include these lower flammability refrigerants in Table 1102.3, but it also contains specific A2L and B2L provisions to address the precautions necessary for the proper use of these products. In particular, high-probability systems using A2L refrigerants for human comfort applications are covered by provisions which include refrigerant concentration limits, mechanical ventilation, ignition sources, compressors and pressure vessels, and refrigerant sensors.
In addition, Chapter 11 addresses other minimum requirements for refrigeration systems such as refrigeration machinery rooms (including ventilation), relief valves, and pressure vessels. Apart from refrigerants, the chapter also addresses minimum requirements for systems that use other mediums such as ammonia and brine systems. For ammonia systems, such systems are required to comply with IIAR 2, IIAR 3, IIAR/ANSI 4, IIAR 5, and IIAR 6.
Chapter 12 Hydronics. Chapter 12 regulates hydronic systems that are part of heating, cooling, ventilation, and conditioning systems. Such piping systems include steam, hot water, radiant heating and cooling, chilled water, steam condensate, condenser water, ground source heat pump systems, snow and ice melt systems, ambient temperature loops, and district ambient temperature loops. Provisions within this chapter addressing ground source heat pumps and ambient temperature loops apply to the hydronic portions of the system. Geothermal energy systems, including ground source heat pumps and ambient temperature loops, are regulated by Chapter 17.
Materials for piping and tubing must meet the working temperature and pressure of the system. In addition, materials must be compatible with the transfer medium to prevent deformation, bursting, or any chemical action between the material and the transfer medium. The allowable joining methods for piping or tubing are provided for application and enforcement purposes.
Chapter 13 Fuel Gas Piping. Chapter 13 regulates gas piping systems in a building, structure or within the property lines of buildings up to 5 psi. Gas piping systems must supply the minimum volume of gas required by each gas appliance to perform their proper operation under working conditions without exceeding the maximum pressure specified by each manufacturer. Because of the hazards associated with fuel gas, it is important to ensure the gas system has been inspected and tested, and that it is safe to turn on the gas supply to the building.
Chapter 14 Process Piping. Chapter 14 regulates process piping that typically is found in refineries. Process piping is considered the piping or tubing portion that transports liquid or gas, which is used directly in research, laboratory, or production process. This chapter may be used with another chapter of the code. For example, refrigeration piping, fuel gas piping, or fuel oil piping may need to comply with this chapter for process piping and the applicable chapter for materials, design, and installation.
Chapter 15 Solar Energy Systems. Chapter 15 refers the user to the Uniform Solar, Hydronics and Geothermal Code (USHGC) for solar energy system requirements. The USHGC contains comprehensive design, installation, and construction requirements for all types of solar thermal systems, such as drainback, thermosiphon, open-loop, and closed-loop systems. The USHGC also addresses installation of solar photovoltaic (PV) systems including array circuit(s), inverter(s), and controller(s) for such systems.
CMC § 1406.0 Medium relevance — show source text
1406.0 Pipe, Tubing, and Fittings.
1406.1 General. Process pipe, tubing, and fittings shall comply with ASME B31.3 and shall be installed in accordance with the manufacturer’s installation instructions. Materials shall be rated for the operating temperatures and pressures of the system, and shall be compatible with the type of liquid.
1406.2 Hazardous Process Piping (HPP). HPP supply piping or tubing in service corridors shall be exposed to view. HPP piping shall be identified in accordance with nationally recognized standards to indicate the material being transported. Liquid HPP piping shall have an approved means for directing spilled materials to an approved containment or drainage system.
Liquid HPP waste or drainage systems shall be installed in accordance with the plumbing code.
1406.2.1 Installation in Exit Corridors and Above Other Occupancies. Hazardous process supply pipe shall not be located within exit corridors, within a portion of a means of egress required to be enclosed in fire-resistive construction, or in concealed spaces in or above
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PROCESS PIPING
areas not classified as Group H Occupancies, except as permitted by this subsection.
Hazardous production material piping and tubing shall be permitted to be installed within the space defined by the walls of exit corridors and the floor or roof above, or in concealed spaces above other occupancies in accordance with Section 1406.2.1.1 through Section 1406.2.1.6.
1406.2.1.1 Automatic Sprinklers. Automatic sprinklers shall be installed within the space unless the space is less than 6 inches (152 mm) in the least dimension.
1406.2.1.2 Ventilation. Ventilation at not less than
6 air changes per hour (ACH) shall be provided. The space shall not be used to convey air from other
areas.
1406.2.1.3 Receptor. Where the piping or tubing is used to transport HPP liquids, a receptor shall be installed below such piping or tubing. The receptor shall be designed to collect discharge or leakage and drain it to an approved location. The 1 hour enclosure shall not be used as part of the receptor.
1406.2.1.4 Separation. HPP supply piping and tubing and HPP nonmetallic waste lines shall be separated from the exit corridor and from an occupancy other than a semi-conductor fabrication facility classified as a Group H Occupancy by construction, as required for walls or partitions that have a fire-protection rating of not less than 1 hour. Where gypsum wallboard is used, joints on the piping side of the enclosure need not be taped, provided the joints occur over framing members. Access openings into the enclosure shall be protected by approved fire assemblies.
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.
Frequently asked questions
Do I always need plans to get a process-piping permit?
The CMC allows the AHJ to require plans, engineering calculations, diagrams, and other data with each permit application; whether you must submit them depends on the AHJ and the scope of work. § 1403.1
Are there different fees for hazardous vs. nonhazardous process piping?
Yes. Table 104.5 distinguishes Hazardous Process Piping (HPP) and Nonhazardous Process Piping (NPP) and further separates fees for 1–4 outlets vs 5 or more outlets (per outlet). Actual dollar amounts are set by the jurisdiction.
What exactly must I list on the permit application?
At minimum, you must show the total number of outlets for each system; the AHJ can require additional information as part of the application. § 1402.1
If I only replace a fitting, do I need a permit?
The CMC’s § 1402.1 makes permits mandatory for install/alter/repair of process piping. The code text does not list a blanket small-repair exception in § 1402.1; local administrative rules or other parts of law may identify minor-repair exemptions — check with the AHJ.
Who sets the exact permit fee amounts and plan-review requirements?
The local Authority Having Jurisdiction (AHJ) sets the fee amounts and may set plan-review and submittal requirements; the CMC provides the fee structure and allows the AHJ to fill in amounts and details (see Table 104.5 and §§ 1402.1 / 1403.1). file
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