View Full Version : Reverse flow check valves/Flashback arrestors
11-22-2005, 09:43 PM
I've been reading that these items need to be tested every 6 months... so how do you test them to ensure that they are working properly?
Also, had several backfires today cutting some thick stock and letting the tip overheat, (won't do that again). Are the built in FB arrestors still OK in my Victor 100FC or should I test it somehow. When everything cooled down and I got to a thinner area, cutting went without incident.
11-22-2005, 10:04 PM
Interesting concept about testing them. I make sure I hear them flutter when adjusting the flow rate, but my torch rig is going on 25yrs old (linde) and hasn't ever been formally "tested." It hasn't blown me up yet, so I think they still work. :)
11-23-2005, 03:31 AM
Real easy to test them, get a small tray with an inch of water in it, take them off, and blow as hard as you can with your mouth in the oposite direction of the flow, with the other end in the pan of water. If you see bubbles, replace them. No bubbles, then they're ok.
11-23-2005, 04:34 AM
Every surface supplied diving helmet has a spring loaded check valve in air supply called a non return valve that is checked before each day's use. Traditional test was to have a smoker try blowing smoke through it. Now USN divers check them with hand pumped vacuum gage. What is never talked about in any manual, check valves that sat overnight or longer with no gas flow through them always failed the test unless you first blew through the valve in flow direction lifting popet off the seat or tapped it open. This was because the soft rubber seat O-ring would take a set. This might also happen when testing torch check valves.
11-23-2005, 08:03 AM
Mine are probably 25-30 yrs old, never thought about checking them, of course I don't use it that much anymore since I aquired the plaz. Thanks Coalsmoke I'll try you method of test and thanks to the others for bringing this item to mind.
11-23-2005, 08:32 AM
Thanks for the replies... I should have figured that out myself! :D
How 'bout the flash arrestors? Any test for them or does the screen material last through the flame? :eek:
11-23-2005, 12:53 PM
my new flash arrestors are one way only, and thus they use the same test. Not sure aboiut the older ones though. At the vary least, visually inspect the screen as good as possible. The thing is, 40 for a new set of flashbakcs is not all that bad when you look at the potential consequences of not having them.
11-23-2005, 01:29 PM
Same problem with testing fuses!.... :confused: :rolleyes: