# Acetylene and oxygen piping



## jpranch (Dec 9, 2009)

I have a welding technology building with long indoor runs of acetylene and oxygen piping. I'm trying to track down the correct testing pressures for inspection and the NFPA Standard that covers this? Any help would be appreciated. jp


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## FM William Burns (Dec 9, 2009)

Re: Acetylene and oxygen piping

JP:

Try NFPA 51, 2007 (Chapter 6) and ASME B31.3


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## FyrBldgGuy (Dec 9, 2009)

Re: Acetylene and oxygen piping

I would agree.

NFPA 51, Standard for the Design and Installation of Oxygen–Fuel Gas Systems for Welding, Cutting, and Allied Processes, 2007 Edition

Chapter 6 Piping Systems

6.1 Materials and Design.

6.1.1 General.

6.1.1.1   Piping and fittings shall comply with ASME B31.3, Process Piping, insofar as it does not conflict with Section 6.1 and except as follows:

(1)Pipe shall be at least Schedule 40, and fittings shall be at least standard weight in sizes up to and including 6 in. nominal.

(2)Copper tubing shall be Type K or L, in accordance with ASTM B 88, Standard Specification for Seamless Copper Water Tube.

6.1.1.2   Piping shall be steel, brass, or copper pipe or seamless copper, brass, or stainless steel tubing, except as provided in 6.1.2 and 6.1.3.

6.1.2 Oxygen Piping Systems.

6.1.2.1*   Materials for fabrication, installation, cleaning, and testing of piping systems shall be selected in accordance with sound engineering practice.

6.1.2.2   Hose connections and hose complying with Section 7.5 shall be permitted to be used to connect the outlet of a manifold pressure regulator to piping, providing the working gauge pressure of the piping is 1.722 MPa (250 psi) or less and the length of the hose does not exceed 1.5 m (5 ft). Hose shall have a minimum bursting gauge pressure of 6.9 MPa (1000 psi).

6.1.2.3   When oxygen is supplied to a service piping system from a low-pressure oxygen manifold without an intervening pressure-regulating device, the piping system shall have a minimum design gauge pressure of 1.722 MPa (250 psi). A pressure-regulating device shall be used at each station outlet where the connected equipment is intended for use at gauge pressure less than 1.722 MPa (250 psi).

6.1.3 Piping forAcetylene and Methylacetylene-Propadiene, Stabilized.

6.1.3.1   Piping shall be steel.

6.1.3.2   Unalloyed copper shall not be used except in listed equipment.

6.1.3.3*   Except in cylinder manifolds,acetylene shall not be piped or utilized at a pressure in excess of 103 kPa (15 psi) gauge or 206 kPa (30 psi) absolute. This provision is not intended to apply to the storage of acetylene in cylinders manufactured to DOT specifications.

6.5 Testing. (Also see 6.1.2.1 for oxygen piping.)

6.5.1   Piping systems shall be tested and proved gastight and leak free in accordance with ASME B31.3, Process Piping.

6.5.2   Where combustible gas lines or other parts of equipment are being purged of air or gas, sources of ignition shall not be permitted near uncapped openings.


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## jpranch (Dec 9, 2009)

Re: Acetylene and oxygen piping

Thanks for the help. So if I'm reading this right we should test the oxygen piping at 250 psi and the acetylene piping at 30 psi? Also, I do not have access to ASME B31.3. Would anyone be willing to copy and paste the testing information for me? 2nd also: piping line labeling? Color coded? Interval? I know I'm asking a lot but really need some help. The Governor is coming to do a grand opening for this new facility on Monday. We just found out yesterday and...... Well, you know the rest!


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## FM William Burns (Dec 9, 2009)

Re: Acetylene and oxygen piping

JP:

I don't have ASME B31.3 and regarding color scheme it's in:

ANSI A13.1, Scheme for Identification of Piping Systems. (Don't have that one either)

I would have cut and pasted the NFPA 51 stuff but didn't want to expose the BB to copyright violations


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## cda (Dec 9, 2009)

Re: Acetylene and oxygen piping

Anyone seen HAZ lately??? Did they retire him out to pasture?? Or Did he fall into a vat of BBQ sauce while inspecting???


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## jpranch (Dec 9, 2009)

Re: Acetylene and oxygen piping

Has, Are you there??? Help!

FM and FyrBldgGuy  Thanks!!! Good stuff.


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## RJJ (Dec 10, 2009)

Re: Acetylene and oxygen piping

HE is most likely taking care of his cat!

JP do you think the Governor will care what color the pipes are?  Or if they have labels!

Are they having lunch after the photo shoot? and are you on the guess list?


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## jpranch (Dec 10, 2009)

Re: Acetylene and oxygen piping

rjj, I'm not invited. But thats quite allright. Not really into those sort of events anyway.


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