torch flash arrestor

Not a problem. Personally I'd plan to get a new one ASAP, but if you need to cut today, getting rid if it for today will be one very minor addition to the usual array of risks that are associated with any use of a torch. It provides some degree of protection from a fairly rare condition. So rare, I've never (to my knowledge) had it. Still, I'd rather have than not - I've also never used an airbag in a car, but I'd rather have one than not.

I actually prefer to have it at the torch end, since the whole point of the thing is to prevent the (rare) propagation of an inside-the-torch flame, and I see no reason to give such a thing the whole hose to play with, nor do I see much opportunity for it to start in the hose, unless the hose is in such terrible shape that it needs to be replaced anyway. Practically speaking, I've never known mine to be doing anything but sitting there, not that I'm anything more than a long-term hobby weldor.

How do you quantify a hazard? The likelihood of anything bad happening is slight, but the consequences can be dire. Photos available at any welding store. I ran small tanks (B acet, R oxy) with no arrestors for some time, never had a problem.

A concrete wall between you and the tanks would be a good idea.

When shutting down the torch, do it slowly. Shut off the oxy first so you don't get a "pop".

Karl, The arrester protects the regulator not you. You don't need it at all, but a torch pop could trash the regulator. Steve

torch pop could trash the regulator.

Good to know. FWIW, I just completed the job, no problem.

Karl

It's like anything else, Karl. 99.999% of the time, nothing happens. When it does, we read about it in the paper. They are not that expensive, and I have been known to have two, one on the reg, one on the torch, just for peace of mind. Do your cut being mindful most of: test connections with Windex, watch for where the slag drops, and make sure all connections are tight.

I didn't know they went out.

It doesn't happen often, but when it does, it's usually ugly.

Steve

Now go get a new one and sleep better.

Steve

Hmm. There must be different philosophies on that one. When I shut off the torch, I turn off the Acetylene first and the Oxy blows the flame away from the torch tip. No pop.

For a flashback, I recall that you're supposed to turn off the oxygen first so the acetylene inside the torch body doesn't have any oxygen to keep the flame inside going. Is that what you meant, or do you routinely shut Oxy off first on your torches?

RWL

I put arresters on both the tank..and the torch end of the hose.

I had a dozen sets...shrug

Gunner

I am the Sword of my Family and the Shield of my Nation. If sent, I will crush everything you have built, burn everything you love, and kill every one of you. (Hebrew quote)

I shut off the oxy first so it doesn't pop.

In 8th grade metal shop, I was taught to shut off the fuel first (acet), then the oxidizer.

I think that was covered, but the thought which prevailed was that the amount of oxy in a torch tip didn't amount to much after it had diluted the acet and the flame was already blown out externally.

-- Some people hear voices. Some see invisible people. Others have no imagination whatsoever.

Just got the paper this morning -- Willamette Valley vintners are working hard to save the grape harvest. If we haven't had the rainiest summer on record it's certainly come close. We've had cool rainy weather alternating with the occasional sunny spell since spring (except for one hot spell in June that fooled us into buying some tomato plants and putting them in).

They're expecting the harvest to be a month late. This week, instead of picking grapes they're picking leaves and winnowing the less-mature bunches from the vines. And I'll bet that even the atheists among them are praying a bit.

The sky _is_ going to fall, Karl. Is that dire enough?

Hope you get 'er done.

BUT:

Uh-huh. No time to do proper maintenance that may prevent a serious explosion, but time for a ball game, is that accurate?

Thanks, Rich

My approach is governed more by experience than by reason. Somewhere back in antiquity I noted that the torch doesn't pop if I turn off the oxy first, so that's how I've been doing it for 35 years or so.

Well, not quite as bad as Obama getting re-elected.

Karl

Yep, no way am I giving up my Sunday P.M. ball game time.

Karl

Gotta stay sane...

Besides -- where are you going to find a welding shop open on Sunday?

"Don Foreman" wrote

My experiences are: when you turn off the O2 first, you have black boogers floating around. If you turn off the acet first, you have no fuel for the fire. Then you experience your first no acet combustion, fueled only by oxygen, which is both exciting and frightening, as in, "Holy Shit, now what do I do?"

Me, I turn off the fuel first, thinking that the most important part of the triangle of fire is fuel. Even if you have oxygen and heat, it is actually possible to continue combustion, but if you remove the fuel, it goes out.

But then, there's oxygen.

It's all relative, but the conversation was about burnback, hose fires, and flame arrestors.

In a perfect world, we might all turn off the oxygen partially, the acet partially, then kill it by turning off either. But in the production world, it all fades into fatigue, and it is hard to remember which one is actually turned off first.

Steve

Fergeddabout the hose fire and subsequent acetylene conflagration, SAVE THE WINE! One must have their priorities in place.

Steve

==============

RWL

=============

=======

======

The only acetylene powered torch that pops for me when shut off is my Prestolite plumbing torch (acetylene & air). Shutting the fuel off first on my OA rig doesn't cause it to pop, and I don't get all the soot floating in the air that shutting off the O2 first yields when the long acetylene flame is burning in room air..

RWL