Acetylene gauge question

[rossow (mn)]

I'm trying to revive my oxyacetylene setup after several years (six or seven) of inside storage but non-use. The acetylene tank's gauge shows plenty of gas, but the pressure-regulating gauge needle sits dead at the zero side. (It's not pegging out in the red zone as bad gauges may do.) By adjusting the valve -- carefully just a tiny bit -- and listening I can hear the pressure change, but the needle doesn't move. I suspect a faulty gauge that hasn't been used for quite a while.

My question: Is there anything special about unscrewing the gauge and replacing it (with tank valve closed, of course) with a new one?

FWIW, the set is a tiny Craftsman outfit from the late '60s I have used for heating up rusty nuts and doing some thin-metal welding and brazing. I've rarely used it for cutting anything. The gauges are 2" diameter, and the gauge thread appears to be 1/8 NPT. An actual Craftsman replacement is, I'm sure, long deceased, but other 2" gauges seem readily available. I've never had anything apart other than to change tanks and to change tips. I don 't want to screw something up if a gauge replacement isn't as simple as I hope, and your expert advice is welcome to help me avoid a big boom.

(Interesting sidebar: Many years ago an O-ring was leaking in the torch, so I went to the Sears parts department to get a replacement. I was told their parts data showed no specific O-ring for that torch and I'd have to buy a whole new torch. So I asked if they had generic O-rings. "Yes, of course we do" -- and so I bought one for a dime -- 10 cents -- and it worked perfectly for years until I set the equipment aside, and it's probably still OK today.)

 

[SkipperII]

Any welding supply will have a proper Acetylene gauge.

 

[caterpillar guy]

As Skipperii said if not most industrial supply places would have one. No reason for any problems if you just have tanks turned off then undcrew gauge and replace with new one.

 

[da.bees]

As others have said, it's only a matter of unscrewing old one and screwing new one in. Not suggesting you you follow my example but I once knocked the tank over smashing gauge. Fearing gauge might leak gas I removed gauge and screwed a brass plug in it's place until I finished the job. Probably used torch a dozen times before getting around to buying a new gauge. Truth is I seldom look at gauges again after opening tank valve.

 

[rossow (mn)]

As others have said, it's only a matter of unscrewing old one and screwing new one in. Not suggesting you you follow my example but I once knocked the tank over smashing gauge. Fearing gauge might leak gas I removed gauge and screwed a brass plug in it's place until I finished the job. Probably used torch a dozen times before getting around to buying a new gauge. Truth is I seldom look at gauges again after opening tank valve.

I have to agree with you and admit I don't pay much attention to the gauge, depending instead on watching the pencil-point flame I use almost exclusively for heating rusted nuts and brazing. I could count on one hand with fingers left over the rare times I have used the cutting torch. Even though I have large tanks, my acetylene is turned on only enough to keep a tiniest flame alive. Still, I do want a working gauge, just to be safe.

 

[miangus]

I would start by tapping it lightly on the back with a Cresant wrench maybe just stuck. If no luck replace the gauge.

 

[SkipperII]

I have to agree with you and admit I don't pay much attention to the gauge, depending instead on watching the pencil-point flame I use almost exclusively for heating rusted nuts and brazing. I could count on one hand with fingers left over the rare times I have used the cutting torch. Even though I have large tanks, my acetylene is turned on only enough to keep a tiniest flame alive. Still, I do want a working gauge, just to be safe.

I AWAYS check my gauges. Made the mistake, many years ago, of not checking. Got complacent, because the three of us in the shop all set them the same. Had someone come into our shop on a weekend, used our torches, and set the acetylene at over 20 psi. I was going to cut the muffler off a Ford cabover on the hoist. Lit the cutting torch, and blew the hose right off the regulator (in the days before blow back valves). I now back off presssure, and bleed the lines, when I'm done.

 

[rossow (mn)]

I AWAYS check my gauges. Made the mistake, many years ago, of not checking. Got complacent, because the three of us in the shop all set them the same. Had someone come into our shop on a weekend, used our torches, and set the acetylene at over 20 psi. I was going to cut the muffler off a Ford cabover on the hoist. Lit the cutting torch, and blew the hose right off the regulator (in the days before blow back valves). I now back off presssure, and bleed the lines, when I'm done.

Good comments. You reminded me that I do indeed, check my gauges when I start a task, because, like you, I always shut off pressure at the tank and bleed the lines so the gauges aren't sitting with pressure on them between projects. Then I reset O & A low-side pressure before I begin fresh work. (I learned OA and stick welding at a trade school long before MIG and TIG became such common things. One instructor's command I remember well is to always bleed the lines when finishing a task.)

 

[SkipperII]

I would start by tapping it lightly on the back with a Cresant wrench maybe just stuck. If no luck replace the gauge.

Any particular size crescent wrench??

 

[Square Eye]

Any particular size crescent wrench??

Tim Taylor recommends at least a 36”.

 

[wh]

Good comments. You reminded me that I do indeed, check my gauges when I start a task, because, like you, I always shut off pressure at the tank and bleed the lines so the gauges aren't sitting with pressure on them between projects. Then I reset O & A low-side pressure before I begin fresh work. (I learned OA and stick welding at a trade school long before MIG and TIG became such common things. One instructor's command I remember well is to always bleed the lines when finishing a task.)

Taught high school welding 30 years. There was no compromise when dealing with acetylene/oxygen. Tanks always shut off, lines bled, torch valves closed, and pressure handles backed out on regulators. I would never touch a system that did not have a working gauge.

 

[Gary Mitchell]

As a last and usually final resort I give whatever the offender might be a whack per what the situation requires. gm

 

[stevieb49829]

I'm trying to revive my oxyacetylene setup after several years (six or seven) of inside storage but non-use. The acetylene tank's gauge shows plenty of gas, but the pressure-regulating gauge needle sits dead at the zero side. (It's not pegging out in the red zone as bad gauges may do.) By adjusting the valve -- carefully just a tiny bit -- and listening I can hear the pressure change, but the needle doesn't move. I suspect a faulty gauge that hasn't been used for quite a while.

My question: Is there anything special about unscrewing the gauge and replacing it (with tank valve closed, of course) with a new one?

FWIW, the set is a tiny Craftsman outfit from the late '60s I have used for heating up rusty nuts and doing some thin-metal welding and brazing. I've rarely used it for cutting anything. The gauges are 2" diameter, and the gauge thread appears to be 1/8 NPT. An actual Craftsman replacement is, I'm sure, long deceased, but other 2" gauges seem readily available. I've never had anything apart other than to change tanks and to change tips. I don 't want to screw something up if a gauge replacement isn't as simple as I hope, and your expert advice is welcome to help me avoid a big boom.

(Interesting sidebar: Many years ago an O-ring was leaking in the torch, so I went to the Sears parts department to get a replacement. I was told their parts data showed no specific O-ring for that torch and I'd have to buy a whole new torch. So I asked if they had generic O-rings. "Yes, of course we do" -- and so I bought one for a dime -- 10 cents -- and it worked perfectly for years until I set the equipment aside, and it's probably still OK today.)

Does your gauge have a screw-on plastic lens? I have an extra one like it but someone dropped the regulator, and bent the crap out of the low-side gauge. Just now I pulled the lens off the gauge and the needle was completely loose on the shaft. You might want to check to see if a little dab of epoxy might fix your problem. steve

 

[rossow (mn)]

Does your gauge have a screw-on plastic lens? I have an extra one like it but someone dropped the regulator, and bent the crap out of the low-side gauge. Just now I pulled the lens off the gauge and the needle was completely loose on the shaft. You might want to check to see if a little dab of epoxy might fix your problem. steve

I'll check tomorrow, but I think mine has a glass lens with a metal frame around it.