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regulator repair question

metalmagpie

Titanium
Joined
May 22, 2006
Location
Seattle
Like others, I have been using an acetylene regulator to run a propane burner. There used to be a torch and regulator repair shop in North Seattle. I knew the owner and had for several decades. He is very experienced and did all of the regulator (and torch) repair work for most of Seattle's industrial base. To first order, he knew everything. I asked him about using acetylene regulators for propane and he told me it would work find but that propane has tar in it which sometimes needs to be cleaned out.

Fast forward to yesterday. I was running this propane burner and noticed the flame kept dying out. I'd set it to e.g. 4 psi and when I came back an hour later the low pressure gauge said 0 and the flame was either out or barely fluttering. I had never run across this symptom before. I kept adjusting the handle to bring the flow back up to normal, then I quit for the day. This morning I didn't touch the regulator, just opened the valve on the tank. Wow, it was up to 12 psi! I turned it down and lit the burner and let it run for a minute or so and then noticed the LP gauge was drifting slowly towards zero.

I swapped in another regulator which solved my propane burner problem.

Today I disassembled the problem regulator. It is a Victor SR-460A. Not truly elderly, plenty old enough to have been made in the US. The first thing I noticed was there was no filter installed in the inlet nipple. I pulled the nipple and nut and yup, I could see straight through. I wonder how many guys have just taken those filters out when they get clogged. I'll have to check my other regulators to see if they are missing their filters too. Anyway, when I pulled the housing cap it revealed a nice metal diaphragm. Removing that, I saw the peripheral O-ring was in good shape. But right away I saw the inside of the regulator was filthy. It looked like .. tar. I didn't see any accumulation that would explain my symptom. I pulled the seat assembly and it all looked fine. I looked up under the housing cap and saw some signs of insect nesting. Old. Not a whole lot.

Anyway, I cleaned everything as best I could and put it all back together. I haven't tested it in service yet because I'm in the middle of a project. Have you heard of a regulator which slowly chokes off flow? Do you know what that is a symptom of? Is it common to find an acetylene regulator without an input filter?

Thanks,

metalmagpie
 
Cheaper seal materials, particularly from the natural rubber groups are compatible with acetylene, but not recommended for lpg. You may get degradation and micro-crumbing which can restrict small orifices prior to seal failure.
 
I went to use my torch today.. and was out of fuel gas... Acetylene. High side gauge is stuck on 100psi and I didn't know it. Must have ran out of fuel the last time I used it.... just as I was finishing whatever it was I was doing.
This is an "AC5" size tank, according to the Airgas sticker on it.
I wrote on the tank when I bought it last... 2013 and $312!!!!!
 
I went to use my torch today.. and was out of fuel gas... Acetylene. High side gauge is stuck on 100psi and I didn't know it. Must have ran out of fuel the last time I used it.... just as I was finishing whatever it was I was doing.
This is an "AC5" size tank, according to the Airgas sticker on it.
I wrote on the tank when I bought it last... 2013 and $312!!!!!
The cheapest way to get acetylene these days is to buy a used cylinder full of gas.
 
Like others, I have been using an acetylene regulator to run a propane burner. There used to be a torch and regulator repair shop in North Seattle. I knew the owner and had for several decades. He is very experienced and did all of the regulator (and torch) repair work for most of Seattle's industrial base. To first order, he knew everything. I asked him about using acetylene regulators for propane and he told me it would work find but that propane has tar in it which sometimes needs to be cleaned out.

Fast forward to yesterday. I was running this propane burner and noticed the flame kept dying out. I'd set it to e.g. 4 psi and when I came back an hour later the low pressure gauge said 0 and the flame was either out or barely fluttering. I had never run across this symptom before. I kept adjusting the handle to bring the flow back up to normal, then I quit for the day. This morning I didn't touch the regulator, just opened the valve on the tank. Wow, it was up to 12 psi! I turned it down and lit the burner and let it run for a minute or so and then noticed the LP gauge was drifting slowly towards zero.

I swapped in another regulator which solved my propane burner problem.

Today I disassembled the problem regulator. It is a Victor SR-460A. Not truly elderly, plenty old enough to have been made in the US. The first thing I noticed was there was no filter installed in the inlet nipple. I pulled the nipple and nut and yup, I could see straight through. I wonder how many guys have just taken those filters out when they get clogged. I'll have to check my other regulators to see if they are missing their filters too. Anyway, when I pulled the housing cap it revealed a nice metal diaphragm. Removing that, I saw the peripheral O-ring was in good shape. But right away I saw the inside of the regulator was filthy. It looked like .. tar. I didn't see any accumulation that would explain my symptom. I pulled the seat assembly and it all looked fine. I looked up under the housing cap and saw some signs of insect nesting. Old. Not a whole lot.

Anyway, I cleaned everything as best I could and put it all back together. I haven't tested it in service yet because I'm in the middle of a project. Have you heard of a regulator which slowly chokes off flow? Do you know what that is a symptom of? Is it common to find an acetylene regulator without an input filter?

Thanks,

metalmagpie
It is some what difficult to remove the porious filter on the inlet without removing the inlet stem and driving it out from the regulator side. Although I have seen bucher removals from the nipple end.
Victor shipped all the SR's with filters, The tar you see is probably dried aceatone from the regulator drawing liquid aceatone off a cylinder that has next to M/T or not vertical in useage sometime in it's life. the A after the 460 designation is for acetylene, although people use them with propane, there not designed internally for propane. Although the gases you are using is relatively low in pressure, EXTREME care should be exercised when home repairing high pressure regulators.
 
We had a welding gas regulator that would randomly shut off gas flow and jump back to normal. It was a huge pain to find that the regulator was the issue.
 








 
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