Welders: those anti-backfire valves?

[Joel_BC]

Question for any of you veteran oxy-fuel welders on the forum here...

You know those little in-line anti-flashback valves we have between our O/A gas-supply hoses and the torch handle? Do they ever need to be replaced, as a matter of routine (like say, I dunno, every five years)? I have no idea, but the thought occurred to me that I should look into it. Thanks.

[Windy in Kansas]

Interesting question. Never even heard of them before today and know that my O/A hoses connect directly without one. 1970s unit.

[Wis Bang 2]

It was the first thing the fire inspector looked for the moment he saw the torch set...then he demanded we attach a fire extinguisher to the cart...It the tank gauges ever catch fire, that's the last extinguisher your gonna use...

I've never seen anyone replacing the anti flashbacks...

[Wis Bang 2]

Originally Posted by Windy in Kansas

Interesting question. Never even heard of them before today and know that my O/A hoses connect directly without one. 1970s unit.

They are small round check valves that look like they belong at the end of the hose where it enters the gauges. Should have been in place by the 70's...

[farminghandyman]

for most units there a add on item,

there are a few different type, some are just check valves and some are anti flash back,

that will actually keep a flame from passing through them,

http://www.google.com/products?q=Fla...N&hl=en&tab=wf

[Joel_BC]

Originally Posted by farminghandyman

there are a few different type, some are just check valves and some are anti flash back, that will actually keep a flame from passing through them

But no one knows of any need to replace them after years of service?

[CrashTestRanch]

Joel_BC
<OPINION>
I wouldn't unless they look corroded or rusted out.
</OPINION>

Check the manufacturers specs on the preventers, they should be able to tell you if they have any seats, o-rings, etc.. that wear or "fail" over time.

I know they're expensive $$$

[SamEwing]

http://files.aws.org/technical/facts/FACT-28.pdf

no specs here but some resources to try

[farminghandyman]

I have never seen a replacement recommendation,

I would suggest if you ever had a flash back or a hose burn back, then replace them if they have never be exposed to damaging use then I would not see any need to replace any more than replacing the regulator, if one is concerned then replace,

[longrider]

No date on them but we always put one on both sides and one at the handle and one at the gauge. Total of 4 on the equiptment.

At $15 dollars each they are well worth it. I saw a regualtor blow one time from a distance. These things ought to be law or at least required coming from the factory on the gear.