CPC · California Plumbing Code

Operational flow pressure-drop tests and medical gas concentration testing before service

Before a medical gas system can be used in California, every user-accessible outlet must pass an operational flow test (specific flows for vacuum and Category 1 oxygen/air outlets) and every pressure gas source and outlet must be concentration-tested after purge to the limits in Table 1324.5.11; these requirements are set out in **§ 1324.5.10**, **§ 1324.5.10.1**, **§ 1324.5.10.2**, and **§ 1324.5.11**.

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Last reviewed: July 6, 2026

What the code requires — 2–4 sentences

Before a piped medical gas or vacuum system is placed in service, the installer must perform an Operational Flow Pressure Drop Test at each station outlet/inlet where users will connect/disconnect equipment and must perform a Medical Gas Concentration Test after purging the system. The operational-flow tests (including specific flow and vacuum thresholds) are required by § 1324.5.10, with vacuum and flow details in § 1324.5.10.1 and § 1324.5.10.2. Concentration analysis, instrumentation requirements, and allowable limits are set out in § 1324.5.11 and its Table 1324.5.11.

The single most important rule: perform the flow/drop test at every user-accessible station and verify gas purity at each source and outlet after purging — if either the flow/pressure or concentration limits in § 1324.5.10–§ 1324.5.11 are not met, the system cannot be placed in service.

Requirements in detail

Which tests, and where

  • Operational Flow Pressure Drop Test: performed at each station outlet/inlet or terminal where the user makes connections/disconnections. § 1324.5.10.

  • Medical Gas Concentration Test: after the system is purged with the system-designated gas, each pressure gas source and outlet must be analyzed for gas concentration (by volume) using instruments designed for the specific gas. § 1324.5.11.

Key numeric thresholds and test parameters (decision table)

Test / measurement Threshold / value Duration / notes Code Reference
Operational flow test — general Performed at every station outlet/inlet or terminal where users connect/disconnect N/A § 1324.5.10
Medical-surgical vacuum inlet flow 3 SCFM (85 Nl/min) drawn at inlet while not reducing adjacent inlet vacuum below 12 inch (305 mm) gauge HgV Must hold while drawing flow § 1324.5.10.1
Oxygen / Medical air outlet transient flow 6 SCFM (170 SLPM) transient flow 3 seconds (Category 1 spaces) § 1324.5.10.2
Concentration — Oxygen USP ≥ 99% oxygen Analyze at each source & outlet with gas-specific instrument Table 1324.5.11 / § 1324.5.11
Concentration — Oxygen 93 USP ≥ 90% and ≤ 96% oxygen — Table 1324.5.11 / § 1324.5.11
Concentration — Nitrous oxide USP ≥ 99% nitrous oxide — Table 1324.5.11 / § 1324.5.11
Concentration — Nitrogen NF ≤ 1% oxygen or ≥ 99% nitrogen — Table 1324.5.11 / § 1324.5.11
Concentration — Medical air USP 19.5% – 23.5% oxygen — Table 1324.5.11 / § 1324.5.11
Concentration — Other gases Named gas ±1% or per specifications Use instrument specific to gas Table 1324.5.11 / § 1324.5.11

Instruments and timing

  • Analysis must be conducted with instruments designed for the specific gas being dispensed; generic gas detectors are not acceptable for certification testing. § 1324.5.11(2).

  • Concentration testing is performed after purging each system with the gas of system designation (i.e., purge first, then test). § 1324.5.11.

Exceptions & special cases

  • The transient 6 SCFM / 3-second requirement in § 1324.5.10.2 specifically applies to outlets serving Category 1 spaces. If the outlet does not serve Category 1 space, this particular transient-flow criterion is not applicable; check the project’s Category classification and other sizing requirements in the code. § 1324.5.10.2.

  • Table 1324.5.11 allows other gases to be tested to named-gas tolerance ±1% or per specification; consult the manufacturer/specification for nonstandard gases. § 1324.5.11 / Table 1324.5.11.

  • The code requires purging before concentration testing; where other sections (e.g., on purge/blowdown) specify test gas and purge method, follow those (see Related provisions below). If you need the detailed blowdown/purge procedure text and it is not on this page, consult the referenced sections.

If a required numeric value or procedure detail you expect is not covered by § 1324.5.10–§ 1324.5.11 in the retrieved text, state that explicitly and consult the referenced NFPA standard and adjacent CPC sections (listed below) for the full procedural text.

Common mistakes

  • Failing to purge the system with the designated gas before concentration testing — § 1324.5.11 requires purge first.
  • Using a gas analyzer that is not specific to the gas being tested (e.g., using a generic combustible sensor rather than an oxygen analyzer) — § 1324.5.11(2) requires instruments designed for the specific gas.
  • Not performing operational flow tests at every user-accessible station — § 1324.5.10 is explicit that tests are required at each outlet/inlet or terminal where users connect/disconnect.
  • Ignoring the vacuum threshold during vacuum tests — the vacuum inlet must draw 3 SCFM without dropping below 12 inch (305 mm) HgV at adjacent inlets (§ 1324.5.10.1).
  • Failing to keep permanent records of the tests (reports and records are required elsewhere in the chapter; see Related provisions).

Worked example — concrete scenario

Scenario: A new Oxygen 93 USP system has been installed to serve an operating room classified as a Category 1 space. Before placing the system in service you must:

  1. Purge the oxygen system with the system-designated gas (Oxygen 93) as required before concentration testing. § 1324.5.11.

  2. Perform the operational flow test at each outlet in the OR:

    • Connect a flow source to the outlet and apply 6 SCFM (170 SLPM) for 3 seconds. If the outlet allows the transient flow for the 3-second period the outlet meets the criterion in § 1324.5.10.2. If the outlet chokes or equipment causes unsafe pressure behavior, it fails. § 1324.5.10.2.

  3. Perform concentration testing at the source and at the outlet:

    • Use an oxygen analyzer calibrated for oxygen and measure by volume.
    • If the analyzer reads 92.3% O2 at a sample outlet and 92.6% O2 at the source, both readings fall within the allowable Oxygen 93 range (≥ 90% and ≤ 96%) in Table 1324.5.11 — pass. § 1324.5.11 / Table 1324.5.11.

  4. Record results in the system test report and submit per certification procedures (see Related provisions). If any test fails (e.g., outlet cannot supply 6 SCFM for 3 seconds, or measured concentration is 89.7% O2), the system must be corrected and retested before being placed in service. § 1324.5.10, § 1324.5.11.

Related provisions

  • § 1324.5.8 — Purging / particulate removal procedures referenced elsewhere for pipeline cleaning.
  • § 1324.5.9 — Final tie-in leak testing and requirement to test pressure gases for operational pressure and gas concentration before use for patient care.
  • § 1324.5.4 — Standing pressure tests and test pressure percentages (context for pressure testing).
  • § 1306.2 — Certification test list items that must be included in reports (flow rate, pressure drop, gas purity, source function).
  • Table 1324.5.11 — Allowed gas concentration limits for each named medical gas (part of § 1324.5.11).

If you need the full procedural text for purging, initial pressure testing, standing pressure tests, or report formatting, consult the cited §§ above and NFPA 99 as referenced by the CPC; the controlling test limits above are from § 1324.5.10, § 1324.5.10.1, § 1324.5.10.2, and § 1324.5.11.

Code references

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

  • CPC § 1324.5.9.4 High relevance — show source text

    1324.5.9.4 Permanent Records. Permanent

    records of these tests shall be maintained in accordance with NFPA 99. [NFPA 99:5.1.12.4.9.6]

    298 2025 CALIFORNIA PLUMBING CODE

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

    HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICAL VACUUM SYSTEMS

    1324.5.10 Operational Flow Pressure Drop Test. Operational flow pressure drop tests shall be performed at each station outlet/inlet or terminal where the user

    makes connections and disconnections. [NFPA 99: 5.1.12.4.10]

    1324.5.10.1 Medical-Surgical Vacuum Inlets. Medical-surgical vacuum inlets shall draw 3 SCFM (85 Nl/min) without reducing the vacuum pressure below 12 inch (305 mm) gauge HgV at any adjacent station inlet. [NFPA 99:5.1.12.4.10.4]

    1324.5.10.2 Oxygen and Medical Air Outlets. Oxygen and medical air outlets serving Category 1 space shall allow a transient flow rate of 6 SCFM (170 SLPM) for 3 seconds. [NFPA 99:5.1.12.4.10.5]

    1324.5.11 Medical Gas Concentration Test. After

    purging each system with the gas of system designation, the following shall be performed:

    (1) Each pressure gas source and outlet shall be analyzed for concentration of gas, by volume.

    (2) Analysis shall be conducted with instruments designed to measure the specific gas dispensed.

    (3) Allowable concentrations shall be as indicated in Table 1324.5.11. [NFPA 99:5.1.12.4.11]

    TABLE 1324.5.11

    GAS CONCENTRATIONS

    [NFPA 99: TABLE 5.1.12.4.11]

    MEDICAL GAS CONCENTRATION


    Oxygen USP    		 ≥99% oxygen


    Oxygen 93 USP    		 ≥90% oxygen≤96%


    Nitrous oxide USP    		 ≥99% nitrous oxide

    Nitrogen NF    		 ≤1% oxygen or≥99% nitrogen

    Medical air USP    		 19.5% - 23.5% oxygen
    Other gases Named gases by ±1%, or per specification

    Part III – Category 2 Piped Gas and Vacuum Systems.

    1325.0 Category 2 Piped Gas and Vacuum Systems.

    1325.1 General. Category 2 piped gas or piped vacuum system requirements shall be permitted when all of the following criteria are met:

    (1) Only moderate sedation (as defined in Chapter 2), minimal sedation (as defined in Chapter 2); or no sedation is performed. Deep sedation and general anesthesia shall not be permitted.

    (2) The loss of the piped gas or piped vacuum systems is likely to cause minor injury to patients, staff, or visitors.

  • CPC § 1324.5.8 High relevance — show source text

    1324.5.8 Particulate Matter. In order to remove any traces of particulate matter deposited in the pipelines as a result of construction, a heavy, intermittent purging of the pipeline shall be done. [NFPA 99:5.1.12.4.6]

    1324.5.9 Final Tie-In Test. Each joint in the final connection between the new work and the existing system shall be leak-tested with the gas of system designation at the normal operating pressure by means of a leak detectant that is safe for use with oxygen and does not contain ammonia. [NFPA 99:5.1.12.4.9.2]

    1324.5.9.1 Vacuum Joints. Vacuum joints shall be tested using an ultrasonic leak detector or other means that will allow detection of leaks in an active

    vacuum system. [NFPA 99:5.1.12.4.9.3] 1324.5.9.2 Pressure Gases. For pressure gases, immediately after the final brazed connection is made and leak-tested, an outlet in the new piping and an outlet in the existing piping that are immediately downstream from the point or area of intrusion shall be purged in accordance with the applicable requirements of Section 1324.5.8. [NFPA 99:5.1.12.4.9.4]

    1324.5.9.3 Positive Pressure Gases. Before the new work is used for patient care, positive pressure gases shall be tested for operational pressure and gas concentration in accordance with Section 1324.5.10 and Section 1324.5.11. [NFPA 99:5.1.12.4.9.5]

    1324.5.9.4 Permanent Records. Permanent

    records of these tests shall be maintained in accordance with NFPA 99. [NFPA 99:5.1.12.4.9.6]

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    HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICAL VACUUM SYSTEMS

    1324.5.10 Operational Flow Pressure Drop Test. Operational flow pressure drop tests shall be performed at each station outlet/inlet or terminal where the user

    makes connections and disconnections. [NFPA 99: 5.1.12.4.10]

    1324.5.10.1 Medical-Surgical Vacuum Inlets. Medical-surgical vacuum inlets shall draw 3 SCFM (85 Nl/min) without reducing the vacuum pressure below 12 inch (305 mm) gauge HgV at any adjacent station inlet. [NFPA 99:5.1.12.4.10.4]

    1324.5.10.2 Oxygen and Medical Air Outlets. Oxygen and medical air outlets serving Category 1 space shall allow a transient flow rate of 6 SCFM (170 SLPM) for 3 seconds. [NFPA 99:5.1.12.4.10.5]

    1324.5.11 Medical Gas Concentration Test. After

    purging each system with the gas of system designation, the following shall be performed:

    (1) Each pressure gas source and outlet shall be analyzed for concentration of gas, by volume.

    (2) Analysis shall be conducted with instruments designed to measure the specific gas dispensed.

  • CPC § 1324.0 High relevance — show source text

    1324.0 Performance Criteria and Testing Category 1 (Gases, Medical Surgical Vacuum). 1324.1 Where Required. Inspection and testing shall be performed on components, or portions thereof, of new, piped medical gas or vacuum systems, additions, renovations, temporary installations, or repaired systems in accordance with Section 1324.2 through Section 1324.5.11, and certified in accordance with Section 1306.0.

    1324.2 Breached Systems. All systems that are breached and components that are subject to additions, renovations, or replacement (e.g., new gas sources: bulk, manifolds, compressors, dryers, alarms) shall be inspected and tested. Systems shall be deemed breached at the point of pipeline intrusion by physical separation or by system component removal, replacement, or addition. Breached portions of the systems subject to inspection and testing shall be confined to only the specific altered zone and components in the immediate zone or area that is located upstream for vacuum systems and downstream for pressure gases at the point or area of intrusion. [NFPA 99:5.1.12.1.3 – 5.1.12.1.5]

    1324.2.1 Reports. The inspection and testing reports shall be submitted directly to the party that contracted for the testing, who shall submit the report through channels to the responsible facility authority and any others that are required. Reports shall contain detailed listings of all findings and results. [NFPA 99:5.1.12.1.6, 5.1.12.1.7] 1324.3 Test Gas. The test gas shall be oil-free, dry nitrogen NF. [NFPA 99:5.1.12.2.1.2]

    1324.4 Initial Piping Blowdown. Piping in medical gas and vacuum distribution systems shall be blown clear by means of oil-free, dry nitrogen NF after installation of the distribution piping but before installation of station outlet/inlet rough-in assemblies and other system components (e.g., pressure/vacuum alarm devices, pressure/vacuum indicators, pressure relief valves, manifolds, source equipment). [NFPA 99:5.1.12.2.2]

    1324.5 Initial Pressure Tests – Medical Gas and Vac- uum Systems. Each section of the piping in medical gas and vacuum systems shall be pressure tested. Initial pressure tests shall be conducted as follows:

    (1) After blowdown of the distribution piping.

    (2) After installation of station outlet/inlet rough-in assemblies.

    (3) Prior to the installation of components of the distribution piping system that would be damaged by the test pressure (e.g., pressure/vacuum alarm devices, pressure/vacuum indicators, line pressure relief valves). [NFPA 99:5.1.12.2.3.1, 5.1.12.2.3.2]

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    HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICAL VACUUM SYSTEMS

    1324.5.1 Shutoff Valve. The source shutoff valve shall

    remain closed during tests specified in Section 1324.5 through Section 1324.5.1.2. [NFPA 99:5.1.12.2.3.3]

  • CPC § 1324.5.7 High relevance — show source text

    1324.5.7 System Verification. Verification tests shall be performed only after all tests required in Section

    1324.3 through Section 1324.5.5.7, Installer Performed Tests, have been completed. [NFPA 99:5.1.12.4.1.1] 1324.5.7.1 Test Gas. The test gas shall be oil-free, dry nitrogen NF or the system gas where permitted.

    [NFPA 5.1.12.4.1.2]

    1324.5.7.2 Approved Tester. Testing shall be conducted by a party technically competent and experienced in the field of medical gas and vacuum pipeline testing and meeting the requirements of ASSE/IAPMO/ANSI 6030, except as required by Section 1324.5.7.3. [NFPA 99:5.1.12.4.1.3]

    Testing shall be performed by a party other than the installing contractor. [NFPA 99:5.1.12.4.1.5]

    Where systems have not been installed by inhouse personnel, testing shall be permitted by personnel of that organization who meet the requirements of Section 1324.5.7.2. [NFPA 99:5.1.12.4.1.6]

    1324.5.7.3 Cryogenic Fluid Testing. Testing of the cryogenic fluid central supply system shall be conducted by a party technically competent and experienced in the field of cryogenic fluid systems and meeting the requirements of ASSE/IAPMO/ANSI 6035, in accordance with the mandatory requirements in CGA M-1. [NFPA 99:5.1.12.4.1.4]

    1324.5.8 Particulate Matter. In order to remove any traces of particulate matter deposited in the pipelines as a result of construction, a heavy, intermittent purging of the pipeline shall be done. [NFPA 99:5.1.12.4.6]

    1324.5.9 Final Tie-In Test. Each joint in the final connection between the new work and the existing system shall be leak-tested with the gas of system designation at the normal operating pressure by means of a leak detectant that is safe for use with oxygen and does not contain ammonia. [NFPA 99:5.1.12.4.9.2]

    1324.5.9.1 Vacuum Joints. Vacuum joints shall be tested using an ultrasonic leak detector or other means that will allow detection of leaks in an active

    vacuum system. [NFPA 99:5.1.12.4.9.3] 1324.5.9.2 Pressure Gases. For pressure gases, immediately after the final brazed connection is made and leak-tested, an outlet in the new piping and an outlet in the existing piping that are immediately downstream from the point or area of intrusion shall be purged in accordance with the applicable requirements of Section 1324.5.8. [NFPA 99:5.1.12.4.9.4]

    1324.5.9.3 Positive Pressure Gases. Before the new work is used for patient care, positive pressure gases shall be tested for operational pressure and gas concentration in accordance with Section 1324.5.10 and Section 1324.5.11. [NFPA 99:5.1.12.4.9.5]

  • CPC § 1324.4 High relevance — show source text

    1324.4 Initial Piping Blowdown. Piping in medical gas and vacuum distribution systems shall be blown clear by means of oil-free, dry nitrogen NF after installation of the distribution piping but before installation of station outlet/inlet rough-in assemblies and other system components (e.g., pressure/vacuum alarm devices, pressure/vacuum indicators, pressure relief valves, manifolds, source equipment). [NFPA 99:5.1.12.2.2]

    1324.5 Initial Pressure Tests – Medical Gas and Vac- uum Systems. Each section of the piping in medical gas and vacuum systems shall be pressure tested. Initial pressure tests shall be conducted as follows:

    (1) After blowdown of the distribution piping.

    (2) After installation of station outlet/inlet rough-in assemblies.

    (3) Prior to the installation of components of the distribution piping system that would be damaged by the test pressure (e.g., pressure/vacuum alarm devices, pressure/vacuum indicators, line pressure relief valves). [NFPA 99:5.1.12.2.3.1, 5.1.12.2.3.2]

    296 2025 CALIFORNIA PLUMBING CODE

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    HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICAL VACUUM SYSTEMS

    1324.5.1 Shutoff Valve. The source shutoff valve shall

    remain closed during tests specified in Section 1324.5 through Section 1324.5.1.2. [NFPA 99:5.1.12.2.3.3]

    1324.5.1.1 Required Test Pressure. The test pressure for pressure gases and vacuum systems shall be 1.5 times the system operating pressure but not less than a gauge pressure of 150 psi (1034 kPa). The test pressure shall be maintained until each joint has been examined for leakage by means of a leak detectant that is safe for use with oxygen and does not contain ammonia. [NFPA 99:5.1.12.2.3.4, 5.1.12.2.3.5]

    1324.5.1.2 Leaks. Leaks, if any, shall be located, repaired (if permitted), replaced (if required), and retested. [NFPA 99:5.1.12.2.3.6]

    1324.5.2 Initial Cross-Connection Test. It shall be

    determined that no cross-connections exist between the

    various medical gas and vacuum piping systems. [NFPA 99:5.1.12.2.4]

    1324.5.2.1 Atmospheric Pressure. All piping systems shall be reduced to atmospheric pressure.

    [NFPA 99:5.1.12.2.4.1]

    1324.5.2.2 Sources of Test Gas. Sources of test

    gas shall be disconnected from all piping systems, except for the one system being tested. [NFPA 99:5.1.12.2.4.2]

    1324.5.2.3 System to Be Charged. The system under test shall be charged with oil-free, dry nitrogen NF to a gauge pressure of 50 psi (345 kPa).

    [NFPA 99:5.1.12.2.4.3]

  • CPC § 1324.5.2.3 Medium relevance — show source text

    1324.5.2.3 System to Be Charged. The system under test shall be charged with oil-free, dry nitrogen NF to a gauge pressure of 50 psi (345 kPa).

    [NFPA 99:5.1.12.2.4.3]

    1324.5.2.4 Check Outlets and Inlets. After the

    installation of the individual faceplates with appropriate adapters matching outlet/inlet labels, each individual outlet/inlet in each installed medical gas and vacuum piping system shall be checked to determine that the test gas is being dispensed only from the piping system being tested. [NFPA 99:5.1.12.2.4.4]

    1324.5.2.5 Repeat Test. The cross-connection test referenced in Section 1324.5.2 shall be repeated for each installed medical gas and vacuum piping system. [NFPA 99:5.1.12.2.4.5]

    1324.5.2.6 Identification of System. The proper labeling and identification of system outlets/inlets shall be confirmed during these tests. [NFPA 99:5.1.12.2.4.6]

    1324.5.3 Initial Piping Purge Tests. The outlets in each medical gas piping system shall be purged to remove any particulate matter from the distribution piping. [NFPA 99:5.1.12.2.5]

    1324.5.3.1 Procedure. Using appropriate adapters, each outlet shall be purged with an intermittent high-volume flow of test gas until the purge produces no discoloration in a clean white cloth.

    [NFPA 99:5.1.12.2.5.1]

    1324.5.3.2 Location. The purging required in Section 1324.5.3.1 shall be started at the closest out let/inlet to the zone valve and continue to the furthest outlet/inlet within the zone. [NFPA 99:5.1.12.2.5.2]

    1324.5.4 Standing Pressure Tests – for Positive Pressure Medical Gas Piping Systems. After successful completion of the initial pressure tests under Section 1324.5 through Section 1324.5.1.2, medical gas distribution piping shall be subjected to a standing pressure test. [NFPA 99:5.1.12.2.6]

    1324.5.4.1 Time Frame for Testing. Tests shall be conducted after the final installation of station outlet valve bodies, faceplates, and all other distribution system components. [NFPA 99:5.1.12.2.6.1]

    1324.5.4.2 Source Valve. The source valve shall be closed during this test. [NFPA 99:5.1.12.2.6.2]

    1324.5.4.3 Length of Testing. The piping systems shall be subjected to a 24-hour standing pressure test using oil-free, dry nitrogen NF. [NFPA 99:5.1.12.2.6.3]

    1324.5.4.4 Test Pressure. Test pressures shall be 20 percent above the normal system operating line pressure. [NFPA 99:5.1.12.2.6.4]

  • CPC § 1324.5.1.1 Medium relevance — show source text

    1324.5.1.1 Required Test Pressure. The test pressure for pressure gases and vacuum systems shall be 1.5 times the system operating pressure but not less than a gauge pressure of 150 psi (1034 kPa). The test pressure shall be maintained until each joint has been examined for leakage by means of a leak detectant that is safe for use with oxygen and does not contain ammonia. [NFPA 99:5.1.12.2.3.4, 5.1.12.2.3.5]

    1324.5.1.2 Leaks. Leaks, if any, shall be located, repaired (if permitted), replaced (if required), and retested. [NFPA 99:5.1.12.2.3.6]

    1324.5.2 Initial Cross-Connection Test. It shall be

    determined that no cross-connections exist between the

    various medical gas and vacuum piping systems. [NFPA 99:5.1.12.2.4]

    1324.5.2.1 Atmospheric Pressure. All piping systems shall be reduced to atmospheric pressure.

    [NFPA 99:5.1.12.2.4.1]

    1324.5.2.2 Sources of Test Gas. Sources of test

    gas shall be disconnected from all piping systems, except for the one system being tested. [NFPA 99:5.1.12.2.4.2]

    1324.5.2.3 System to Be Charged. The system under test shall be charged with oil-free, dry nitrogen NF to a gauge pressure of 50 psi (345 kPa).

    [NFPA 99:5.1.12.2.4.3]

    1324.5.2.4 Check Outlets and Inlets. After the

    installation of the individual faceplates with appropriate adapters matching outlet/inlet labels, each individual outlet/inlet in each installed medical gas and vacuum piping system shall be checked to determine that the test gas is being dispensed only from the piping system being tested. [NFPA 99:5.1.12.2.4.4]

    1324.5.2.5 Repeat Test. The cross-connection test referenced in Section 1324.5.2 shall be repeated for each installed medical gas and vacuum piping system. [NFPA 99:5.1.12.2.4.5]

    1324.5.2.6 Identification of System. The proper labeling and identification of system outlets/inlets shall be confirmed during these tests. [NFPA 99:5.1.12.2.4.6]

    1324.5.3 Initial Piping Purge Tests. The outlets in each medical gas piping system shall be purged to remove any particulate matter from the distribution piping. [NFPA 99:5.1.12.2.5]

    1324.5.3.1 Procedure. Using appropriate adapters, each outlet shall be purged with an intermittent high-volume flow of test gas until the purge produces no discoloration in a clean white cloth.

    [NFPA 99:5.1.12.2.5.1]

  • CPC § 6.8947 Medium relevance — show source text

    major gas for back-
    ground/minor gas for text|None| |Nonmedical air and dental air|––|Yellow and white diagonal stripe/black|None| |Nonmedical vacuum and dental
    vacuum|––|White and black diagonal stripe/black boxed|None| |Laboratory air|––|Yellow and white checkerboard/black|None| |Laboratory vacuum|––|White and black checkerboard/black boxed|None| |Instrument air|––|Red/white|50–185 psi|

    For SI units: 1 pound-force per square inch = 6.8947 kPa, 1 inch of mercury vacuum (HgV) = 3.386 kPa

    1305.2 Minimum Flow Rates. Medical gas and vacuum systems shall be capable of supplying the flow rates listed in Table 1305.2.

    1305.3 Minimum Station Outlets and Inlets. Station outlets and inlets for medical gas and vacuum systems shall be provided as listed in Table 1305.3.

    1306.0 System Certification. 1306.1 Certification. Prior to a medical gas or vacuum system being placed in service, such system shall be certified in accordance with Section 1306.2.

    1306.2 Certification Tests. Certification tests, verified and attested to by the certification agency, shall include the following:

    (1) Verifying in accordance with the installation requirements.

    (2) Testing and checking for leakage, correct zoning, and identification of control valves.

    (3) Checking for identification and labeling of pipelines, station outlets, and control valves.

    (4) Testing for cross-connection, flow rate, system pressure drop, and system performance.

    (5) Functional testing of pressure relief valves and safety valves.

    (6) Functional testing of sources of supply.

    (7) Functional testing of alarm systems, including accuracy of system components.

    (8) Purge flushing of system and filling with specific source

    gases.

    (9) Testing for purity and cleanliness of source gases.

    (10)Testing for specific gas identity at each station outlet. 1306.3 Report Items. A report that includes the specific items addressed in Section 1306.2, and other information required by this chapter, shall be delivered to the Authority Having Jurisdiction prior to acceptance of the system. 1306.4 Components. Functioning of alarm components shall be verified in accordance with the testing and monitoring requirements of the manufacturer and the Authority Having Jurisdiction.

    TABLE 1305.2

    MINIMUM FLOW RATES (cubic feet per minute)

    MEDICAL SYSTEM FLOW RATE

    Oxygen    		 0.71 CFM per outlet1

    Nitrous Oxide    		 0.71 CFM per outlet1

    Medical Compressed Air    		 0.71 CFM per outlet1

    Nitrogen    		 15 CFM free air per outlet

    Vacuum    		 1 SCFM per inlet2

    Carbon Dioxide    		 0.71 CFM per outlet1

    Helium    		 0.71 CFM per outlet

    For SI units: 1 cubic foot per minute (CFM) = 0.47 L/s

  • CPC § 6.8947 Medium relevance — show source text

    For SI units: 1 pound-force per square inch = 6.8947 kPa, 1 inch of mercury = 3.386 kPa

    1323.1.6 Engineering Methods. For conditions other than those covered by Section 1323.1.4, such as longer runs of greater gas or vacuum demands, the size of each medical gas or vacuum piping system shall be determined by standard engineering methods acceptable to the Authority Having Jurisdiction, and each system shall be so designed that the total pressure drop or gain between the source equipment and an outlet or inlet shall not exceed the allowable pressures shown in Table 1305.1. 1323.2 Pipe Protection. Piping shall be protected against freezing, corrosion, and physical damage. [NFPA 99:5.1.10.11.2] 1323.2.1 Exposed Piping. Piping exposed in corridors and other areas where subject to physical damage from the movement of carts, stretchers, portable equipment, or vehicles shall be protected. [NFPA 99:5.1.10.11.2.1] 1323.2.2 Underground Piping. Piping underground within buildings or embedded in concrete floors or walls shall be installed in a continuous conduit. [NFPA 99:5.1.10.11.2.2]

    TABLE 1323.1.5(1) SYSTEM SIZING – FLOW REQUIREMENTS FOR STATION OUTLETS AND INLETS [1]

    Notes: 1 Flow rates of station outlets and inlets in accordance with Table 1305.2. 2 The minimum system flow is the average outlets and inlets flow times the number of station outlets and inlets times the diversity percentage.

    TABLE 1323.1.5(2) MAXIMUM PERMITTED PRESSURE LOSS IN

    MEDICAL GAS AND MEDICAL VACUUM SYSTEMS

    For SI units: 1 pound-force per square inch = 6.8947 kPa, 1 inch of mercury = 3.386 kPa

    2025 CALIFORNIA PLUMBING CODE 289

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

    HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICAL VACUUM SYSTEMS

    TABLE 1323.1.4(1) PRESSURE LOSS FOR MEDICAL AIR

    TABLE 1323.1.4(2) PRESSURE LOSS FOR NITROGEN

    FLOW RATE
    (SCFM)1    		 PRESSURE DROP (psi) PER 100 FEET2 Col3 Col4
    FLOW RATE
    (SCFM)1
    		 1⁄2 INCH PIPE
    		 3⁄4 INCH PIPE
    		 1 INCH PIPE
    0.35 0.004 0.001 –
    0.71 0.012 0.003 –
    1.06 0.023 0.005 –
    1.41 0.037 0.007 –
    1.77 0.055 0.011 –
    2.12 0.075 0.015 –
    2.47 0.097 0.019 –
    2.82 0.123 0.024 –
    3.18 0.
  • CPC § 1306.3 Medium relevance — show source text

    (3) Checking for identification and labeling of pipelines, station outlets, and control valves.

    (4) Testing for cross-connection, flow rate, system pressure drop, and system performance.

    (5) Functional testing of pressure relief valves and safety valves.

    (6) Functional testing of sources of supply.

    (7) Functional testing of alarm systems, including accuracy of system components.

    (8) Purge flushing of system and filling with specific source

    gases.

    (9) Testing for purity and cleanliness of source gases.

    (10)Testing for specific gas identity at each station outlet. 1306.3 Report Items. A report that includes the specific items addressed in Section 1306.2, and other information required by this chapter, shall be delivered to the Authority Having Jurisdiction prior to acceptance of the system. 1306.4 Components. Functioning of alarm components shall be verified in accordance with the testing and monitoring requirements of the manufacturer and the Authority Having Jurisdiction.

    TABLE 1305.2

    MINIMUM FLOW RATES (cubic feet per minute)

    MEDICAL SYSTEM FLOW RATE

    Oxygen    		 0.71 CFM per outlet1

    Nitrous Oxide    		 0.71 CFM per outlet1

    Medical Compressed Air    		 0.71 CFM per outlet1

    Nitrogen    		 15 CFM free air per outlet

    Vacuum    		 1 SCFM per inlet2

    Carbon Dioxide    		 0.71 CFM per outlet1

    Helium    		 0.71 CFM per outlet

    For SI units: 1 cubic foot per minute (CFM) = 0.47 L/s

    Notes: 1 A room designed for a permanently located respiratory ventilator or anesthesia machine shall have an outlet capable of a flow rate of 6.36 CFM (3.0 L/s) at the station outlet. 2 For testing and certification purposes, individual station inlets shall be capable of a flow rate of 3 SCFM (1.4 L/s), while maintaining a system pressure of not less than 12 inches of mercury (41 kPa) at the nearest adjacent vacuum inlet.

    2025 CALIFORNIA PLUMBING CODE 277

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

    HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICAL VACUUM SYSTEMS

    TABLE 1305.3

    MINIMUM OUTLETS AND INLETS PER STATION

    LOCATION OXYGEN MEDICAL
    VACUUM    		 MEDICAL
    AIR    		 NITROUS
    OXIDE    		 NITROGEN HELIUM CARBON
    DIOXIDE
    Patient rooms for medical/surgical,
    obstetrics,
  • CPC § 1323.1.5 Medium relevance — show source text

    (6) Add the pressure loss for each section of piping, from the source equipment location to the outlet or

    inlet, to determine the total system pressure loss to each outlet or inlet. The total system pressure loss in the piping to each outlet or inlet shall not exceed the values specified in Table 1323.1.5(2).

    TABLE 1323.1.5(1) SYSTEM SIZING – FLOW REQUIREMENTS FOR STATION OUTLETS AND INLETS [1]

    NUMBER OF
    OUTLETS AND
    INLETS
    TERMINAL
    UNITS PER
    FACILITY    		 DIVERSITY
    PERCENTAGE OF
    AVERAGE FLOW
    PER OUTLETS
    AND INLETS
    TERMINAL UNITS    		 MINIMUM PERMISSIBLE
    SYSTEM FLOW OF ALL
    PRESSURIZED MEDICAL
    GAS SYSTEMS2
    (standard cubic feet per minute)

    1–10    		 100% Actual Demand

    11–25    		 75% 7.0

    26–50    		 50% 13.1

    51–100    		 50% 17.5

    Notes: 1 Flow rates of station outlets and inlets in accordance with Table 1305.2. 2 The minimum system flow is the average outlets and inlets flow times the number of station outlets and inlets times the diversity percentage.

    TABLE 1323.1.5(2) MAXIMUM PERMITTED PRESSURE LOSS IN

    MEDICAL GAS AND MEDICAL VACUUM SYSTEMS

    TYPE OF SYSTEM MAXIMUM ALLOWABLE SYSTEM
    PRESSURE LOSS (psi)

    Medical Air    		 5

    Nitrogen    		 15

    Nitrous Oxide    		 5
    Carbon Dioxide 5


    Oxygen    		 5


    Medical Vacuum    		 4 inches of mercury

    For SI units: 1 pound-force per square inch = 6.8947 kPa, 1 inch of mercury = 3.386 kPa

    1323.1.6 Engineering Methods. For conditions other than those covered by Section 1323.1.4, such as longer runs of greater gas or vacuum demands, the size of each medical gas or vacuum piping system shall be determined by standard engineering methods acceptable to the Authority Having Jurisdiction, and each system shall be so designed that the total pressure drop or gain between the source equipment and an outlet or inlet shall not exceed the allowable pressures shown in Table 1305.1. 1323.2 Pipe Protection. Piping shall be protected against freezing, corrosion, and physical damage. [NFPA 99:5.1.10.11.2] 1323.2.1 Exposed Piping. Piping exposed in corridors and other areas where subject to physical damage from the movement of carts, stretchers, portable equipment, or vehicles shall be protected. [NFPA 99:5.1.10.11.2.1] 1323.2.2 Underground Piping. Piping underground within buildings or embedded in concrete floors or walls shall be installed in a continuous conduit. [NFPA 99:5.1.10.11.2.2]

    TABLE 1323.1.5(1) SYSTEM SIZING – FLOW REQUIREMENTS FOR STATION OUTLETS AND INLETS [1]

  • CPC § 11.0 Medium relevance — show source text

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

    This state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.0.

    2 2025 CALIFORNIA PLUMBING CODE

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

    CHAPTER 1

    ADMINISTRATION

    DIVISION I

    CALIFORNIA ADMINISTRATION

    1.1.0 General.

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

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

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

Frequently asked questions

Who must perform the operational flow and concentration tests?

Testing must be performed by the party technically competent in medical gas and vacuum pipeline testing per the certification requirements; the code requires verification and certification in the chapter test and certification sections. See § 1324.5.7 and § 1306.2 for tester and certification requirements.

Do I need to test every outlet even if it’s not used immediately?

Yes — § 1324.5.10 requires operational flow pressure drop tests at each station outlet/inlet or terminal where users make connections/disconnections. All installed outlets intended for user connections should be tested.

What instrument should I use for oxygen concentration testing?

Use an analyzer specifically designed and calibrated for oxygen concentration measurement (an oxygen gas analyzer). § 1324.5.11(2) requires instruments designed to measure the specific gas dispensed.

If an outlet fails the 6 SCFM transient test, what do I do?

Repair or correct the piping, fittings, or terminal device causing the restriction, then retest. The system may not be used for patient care until it meets the criteria in § 1324.5.10.2 (and the overall certification requirements).

Are the concentration limits absolute?

Concentration limits in Table 1324.5.11 are the allowable ranges for certification testing. For nonstandard gases, follow the “Other gases” row (named gas ±1% or per specification). § 1324.5.11 / Table 1324.5.11.

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