Flashback Arrestor "gurgling" and vibrating on O/A setup?

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Hi,I posted this in the safety forum, but havent got a response. So though I might have better luck here.When I have my two torch mount flashblack arrestors on, and I turn on the acetylene, everything is fine. Then I turnon my oxygen and the torch will begin to vibrate and there is a gurgling/flickering type noise coming from one of the flashback arrestors. I had the acetylene set at 5 psi, and oxygen at 10-12 psi.I believe it is coming from the acetylene arrestor, although I cant be sure because they are so close together.So the oxygen being on seems to be causing it. I cracked the cylinders, purged the regulators, purged the hoses, purgedthe arrestors, then put the torch on.Here is what I have tried:Took the arrestors off: No sound, no vibration. The problem seems to go away.Turned up the pressure on the oxygen(while arrestors on): just got louder.I dont have another welding torch, but i do have a cutting torch. Do you think I should try that to completely rule out the torch handle?I am using a Smith Medium Duty kit. I bought it off ebay, and it was "new" however it was opened. The flashback arrestors were new in their sealed package. Model number for the kit: MTA-30510Model number on flashback arrestors packaging: H743I am 100% fine with replacing the arrestors, just want to be sure it is actually them and not some underlying problem. Or find out if it is nothing to worry about.Last edited by Montang; 04-01-2014 at 01:15 PM.
Reply:Does the torch function normally? Could it be something is screwed up with the mixing chamber and the higher oxygen pressure is causing a reversion in the acetylene hose?
Reply:What happins when you turn the oxy down to 5psi?
Reply:I had the same issue when I put flashback arrestors on my torch. I found the stock check valves to open easily, but the flashback arrestor valves took a lot more pressure to open, which caused them to stutter open and closed instead of staying open. See my old thread for details: http://weldingweb.com/vbb/showthread.php...sue&highlight=I ended up using check valves only and following good safety practices. As my LWS guy said when I asked what to use instead of the ones I'd bought - guys have been using these torches safely for many decades without flashback arrestors. He said it was probably because I was doing such small work with low pressures and flow rates.
Reply:Hi guys, thanks for the replies.I talked with a Smith representative and she said there wasnt any danger and she also told me to run both oxygen and acetylene at 10 psi. I did and it seemed to lower the noise and vibration, but it was still there. I have been welding all weekend with it with no problem though. She is going to call on monday to find out if the dual 10 psi resolved the issue, so I will see what she says.Will post it here in case anyone every has the same problem.