differences between welding gases
differences between welding gases
(OP)
I want to know the differences between the Backing gas, Trailing gas and the Shielding gas, Also the Standard(by details) that these words are defined in it(I quess in ASME Sec. ix)
Would you help me please!
I'm a new comer to this Website.
Thank you.
Would you help me please!
I'm a new comer to this Website.
Thank you.





RE: differences between welding gases
For backing gas, specifically look at ASME Section IX, QW-492 Definitions. Also, look at the specific welding process within the Definitions where the function of shielding gas is described (e.g. GTAW process). Trailing gas would be considered similar to shielding based on welding process and material, but is not technically defined in Definitions.
AWS 5.32 Specification for Shielding Gases
You have all you need.
RE: differences between welding gases
RE: differences between welding gases
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RE: differences between welding gases
I'm not looking at PAW, I just want to answer the question asked by my QC Manager, "the differences between these three". Anyway I appreciate you, the link was useful.
Thanks.
RE: differences between welding gases
Shielding gas is the one emanating from the GTAW 'Tig' torch, or the GMAW 'Mig/MAG' gun, to purge the area of the top of the weld puddle..
Trailing gas is additional gas flow that follows [trails] the torch/gun, and provides a longer purge time. Titanium welding requires trailing gas.
Backing gas is the internal purge of a pipe or fitting, that keeps the back side of easily oxidized metals from getting gross coats of oxudation "sugaring" [looks like lumpy brown sugar]. Stainless, Titanium, Inconel all require purging. Anly Sect. IX calls it "Backing Gas". All the 'field hands' refer to it as a purge.
And that is a pretty good reference manual racookpe1978 attached. Thanks.
RE: differences between welding gases
Thanks.
RE: differences between welding gases
To allow the welded metal to cool to a temperature ( away from oxygen) to where it is no longer reactive.
B.E.
The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor
RE: differences between welding gases
and also which gases are used to trail?
RE: differences between welding gases
RE: differences between welding gases
RE: differences between welding gases
Some folks, especially Europeans, use nitrogen to purge pipes [backing gas]. Nitrogen is NOT inert, just fairly unreactive to metals. Stay with argon. At leaa than $30 per bottle fill-up, it is the obvious choice.
RE: differences between welding gases
RE: differences between welding gases
If a welding term or deninition is not included in the applicable fabrication code, ASME, AWS, API, and military welding standards reference AWS A3.0 for welding and brazing terms and deinitions.
Best regards - Al
Best regards - Al