Oxy-acetelyne Safety

[JWELD]

I know that is probaly spelled wrong, but oh well.

Question: I know that "gas flow cheeck valves" on hoses are a must and have always used them. Has anyone witnessed a blow up from this??

[Blondie_486]

JWELD,

I've never witnessed an explosion or what you'd consider a blow up, but I have seen a torch backfire through the handle and burn the hoses in high school shop class. Of course the "class clown" was welding with the torch at the time too, that may have had something to do with it.

Blondie

[Welder99]

Jweld,
The check valves or so called (Flashback resistors).I have witnessed a flash back into the torch before,most of the time is a continued popping and shreek whisling sound at the end of the torch.when this happened (the flash back the valves,which is a one way valve) in line stopped it from going back into the regulator and then possibly the tank.as to have witnessed it without the valves?,NOPE...and hope i never do.I have seen a Tank that was ripped open like a can opener from the top to the bottom.(a result of not having flash back valves in place.)it was on display at Hobart welding school here in Ohio.most of the time its from a result of either a lean of rich mixture of gasses at the torch.one way to notice this is happening is when you are using a cutting torch and bump the tip against the metal and the flame goes out as the result.then the tip that is still hot ignites the fuel back into the torch head,that is the beginning of a flash back.alot of people that own or use cutting or brazing torches have never been schooled about the dangers that can result in inproper use.im sure there is going to be more people post here about this subject.i know ive only scrapped the tip of the ice berg on this subject.i hope this info is of some help....

good luck....(welder99)

[Paul Seaman]

Thanks guys safety is an every minute requirement and these things keep me thinking and I usually think of myself as safe but my torch doesn't have arrestors on it --yet!!!!!!

Thanks again!

[HAWK]

JWELD,

Bottom line: If you OA rig is not equipped with flash back arrestors then please purchase and install them. This can be done for around $50 for a set-one on each line between the torch body and the hoses. It is not worth the risk!

[JWELD]

Hawk:
I have always had the "arrestors" but just wanted to know thier importance. Thanks

[Blondie_486]

Jweld, HAWK, Pjseaman & Welder99,

I was in at my local welding supplier last week and was looking at the Victor torches on display and noticed the check valves are now BUILT into the torch handle so there's no way you can operate without them. Also it's a good idea to have a set installed at the guages too, you never know when some dumb blonde will drop a piece of hot metal on the hoses or accidentely lay them across something hot... errr my hoses started out as 20' hoses but now they're only about 12'. No they're not scabbed together with hose clamps from the local parts store, I had them crimped again by the local welding supplier.

At any rate it won't be long until you won't be able to buy a torch without the check valves already installed in them and perhaps the regulators will be next? Who knows?

Blondie

[HAWK]

Blondie,

As far as I know Victor started putting the valves into their torch heads about 3 years ago. I have not seen this feature on any other brand or "off brand" torches. Have you?

[Blondie_486]

HAWK,

So far as I've noticed up to this point it's just been the Victors. I've used Victor torches since I was a kid. But next time I'm somewhere that sells other brands and Harbor Freight I'll look and see. That's a good point!

Blondie

[HAWK]

Blondie,

Thanks. That is really only for the sake of argument. I far as I am concerned Victor torches are the only ones made!

[Blondie_486]

HAWK,

Victor torches and Miller welders. It doesn't get any better.

I guess for us non drinkers Miller time means time to go fire up the welder!!

Blondie

[HAWK]

10-4! But I have to say sometimes Miller time gets old when the customer does not want to pay. Three weeks ago a "regular" customer calls and asked me to make a repair. I did the work and sent a bill for $125 plus tax. I had 1 hour travel, 1/2 hour weld time with MIG, 1/2 hour set up and clean up time. Total hours [email protected]/HR. He paid the bill, in line on an hourly basis with all other work in the last 2 years, but said someone else could do it cheaper and asked me to drop my rates. I simply said "get the other guy to do your work". I suspect he will call me back after a few jobs, but could be wrong. We have a couple of new guys here in town trying to get started and are absolutely ruining the local market with their cheap rates. I cannot work for $35-$40/hour.

[Paul Seaman]

Do you guys think that $55 is better spent toward a new torch handle that has the arrestors built in? Mine is an old craftsman built by I think Harris. It works well when I need it which isn't often, mostly disassembly of stubborn car parts.

[Blondie_486]

pjseaman,

Well the decision is ultimately yours but if you do buy a new handle with the arrestors built in you'll most likely have to buy a new cutting head and welding tips too. I'm not sure if Harris makes a handle with built in arrestors or not but even if they do don't assume your Craftsman/Harris cutting head and tips will fit. Craftsman has this habbit of having things built to THEIR specs so parts are NOT interchangeable with the manufacturers original. For instance I had a Craftsman drill and one of the gears broke in it. It looked just like a Black & Decker drill that was being sold around the same time. I found out that it was in fact manufactured by Black & Decker but the B&D gear wouldn't fit in the drill because the drill was manufactured to Craftsman's specifications. I think the B&D parts guy said the only interchangeable part was the brushes.

So if you're going to get a new Harris handle make sure your cutting head and welding tips will work in it before you lay down the green. Otherwise you'll probably be less money putting tne inline arrestors on.

Blondie

[glockdoc]

I have a Craftsman set from the mid '80s and it is made by Harris. The Sears stuff has a few shortcuts compared to the Harris labeled stuff. Aluminum handle versus polished brass, shorter stainless tubes on the Sears than the Harris cutting attachment. I have both and everything is interchangable. Mine came with the check valves attached. Plan on getting rid of the Sears torch stuff as it will not interchange with Victor or Smith (at least in my case). Regs will of course work. I recommend a check valve/arrestor that attaches to your regs, never did like the ones that screw onto the handle. Hoses will not be protected, however. It is my understanding that to get into an explosive situation a gas mixture has to get back into the cylinder. One way is the torch mixer/tip gets plugged so gasses flow from one cylinder into the other. But then gas at 30psi will not go into a cylinder that's at 100 or 200psi. A much more likely situation is when one tries to suck that last bit of gas out of a bottle. Seen where someone tried to get the last bit of acety, when it depleted the welding tip turned into a minature cutting tip when only oxy came out. If the tip had plugged, oxy could have theoretically back-flowed into the acety cyl.