1309.8 Nitrogen Purge.

When brazing, joints shall be continuously purged with oil-free, dry nitrogen NF to prevent the formation of copper oxide on the inside surfaces of the joint.

[NFPA 99:5.1.10.4.5.1]

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1309.8.1 Source. The source of the purge gas shall be monitored, and the installer shall be audibly alerted when the source content is low. [NFPA 99:5.1.10.4.5.2] 1309.8.2 Flow Rate Control. The purge gas flow rate shall be controlled by the use of a pressure regulator and flowmeter, or combination thereof.

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Other aqueous cleaning solutions shall be permitted to be used for on-site recleaning provided that they are as recommended in the mandatory requirements of CGA G4.1. [NFPA 99:5.1.10.4.3.10, 5.1.10.4.3.11] 1309.6.8 Contaminated Materials. Material that has become contaminated internally and is not clean for oxygen service shall not be installed. [NFPA 99:5.1.10.4.3.12] 1309.6.9 Timeframe for Brazing. Joints shall be brazed within 8 hours after the surfaces are cleaned for brazing. [NFPA 99:5.1.10.4.3.13]

Pressure regulators alone shall not be used to control purge gas flow rates. [NFPA 99:5.1.10.4.5.3, 5.1.10.4.5.4] 1309.8.3 Oxygen Analyzer. In order to ensure that all ambient air has been removed from the pipeline prior to brazing; an oxygen analyzer shall be used to verify the effectiveness of the purge. The oxygen analyzer shall read below 1 percent oxygen concentration before brazing begins. [NFPA 99:5.1.10.4.5.5] 1309.8.4 During Installation. During and after installation, openings in the piping system shall be kept sealed to maintain a nitrogen atmosphere within the piping to prevent debris or other contaminants from entering the system. [NFPA 99:5.1.10.4.5.6] 1309.8.5 Discharge Opening. While a joint is being brazed, a discharge opening shall be provided on the opposite side of the joint from where the purge gas is being introduced. [NFPA 99:5.1.10.4.5.7] 1309.8.6 Temperature of Joint. The flow of purge gas shall be maintained until the joint is cool to the touch.

[NFPA 99:5.1.10.4.5.8] 1309.8.7 Opening to be Sealed. After the joint has cooled, the purge discharge opening shall be sealed to

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284 2019 CALIFORNIA PLUMBING CODE

any other purpose or distributed to any other perso ns HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICAL VACUUM SYSTEMS or parties.

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(6) Permanent records of these tests shall be maintained

in accordance with NFPA 99. [NFPA 99:5.12.3.9.6] 1309.8.10 Autogenous Orbital Welding Process. When using the autogenous orbital welding process, joints shall be continuously purged inside and outside with inert gas(es) in accordance with the qualified welding procedure. [NFPA 99:5.1.10.4.5.12]