O/A Torch Question

[Cap-n-Cray]

Is it this kit?

Can you try disconnecting one of the hose (Oxygen) at the torch body. Open the Acetylene to see if the acetylene come back though the torch body. Can you stop it by putting you finger over the disconnected side? Does it come out the tip? Is there something blocking the torch body at the tip? The gas is mixed in the tip if I remember correctly. There are two "O" rings on the tip.

Cary

 

[Lazy]

Acetylene bottle is only about 2 years old and it's still showing plenty of pressure in the bottle.


Hi
Pressure means nothing, the only way to tell if you have acetylene is to weigh the bottle and subtract the tare weight. leave the oxy off and if you can't light the torch then chances are you are out of gas and the pressure you see is just acetone.

Charlie

 

[Gary Fowler]

Your problem it that the oxygen is bleeding back through the torch head connection where it screws on to the mixing barrel (that is the part with the 2 valves where the hoses attach. You either have the cutting head nut not tightened where the two connect or you have one or both orings bad on the cutting head. You should have 2 orings on the cutting head, a small one and a larger one. The small one has to seal the high pressure oxygen or it will bleed back into your mixing barrel and back into your acetylene tank if you dont have any check valves installed. This is potentially very dangerous situation. But it is easy to correct, just tighten the cutting head and if it still is increasing the pressure on the Acetylene gauge take it apart and check the o-rings and replace as necessary.

 

[djradz]

Your problem it that the oxygen is bleeding back through the torch head connection where it screws on to the mixing barrel (that is the part with the 2 valves where the hoses attach. You either have the cutting head nut not tightened where the two connect or you have one or both orings bad on the cutting head. You should have 2 orings on the cutting head, a small one and a larger one. The small one has to seal the high pressure oxygen or it will bleed back into your mixing barrel and back into your acetylene tank if you dont have any check valves installed. This is potentially very dangerous situation. But it is easy to correct, just tighten the cutting head and if it still is increasing the pressure on the Acetylene gauge take it apart and check the o-rings and replace as necessary.

Not that I disagree, but it seems something more is wrong. I've not read yet where he has gottern any acetylene to flow no matter what he has done.

Maybe trying just acetylene with the oxygen tank valve shut off for starters?

 

[BrentD]

Ok, tried this.... Removed the tip. Double checked that BOTH control valves on the handle were closed. Disconnected the oxygen hose from the handle and turned on the Acetylene. Sure enough acetylene came out the Oxygen connector on the handle. Cobbled together a fitting from some tubing and an air compressor pressure gauge and stuck it on the connector where the oxygen would connect. Pressure of acetylene coming out the oxygen fitting is roughly the same as what I set at the acetylene regulator.

Verified that at no time was any gas coming out of the end of the torch body where the tip would connect.

Then I reversed the setup, hooked the oxygen back up and disconnected the acetylene hose. Turned on the oxygen and oxygen came out the acetylene hose connector. Again, nothing came out the holes where the tip would connect.

Reconnected both hoses and turned on Acetylene only and was able to light the torch, but oxygen regulator pressure rose to match acetylene pressure. Oxygen control valve on the torch was fully closed.

Turned Oxygen on at the regulator but left oxygen control valve on torch tip fully closed. Flame behaved as if the oxygen control valve as fully opened and oxygen was only being adjusted at the regulator. I kept increasing oxygen flow at the regulator until the flame went out. Once I passed the pressure of the acetylene, the acetylene pressure gauge started to rise with the oxygen and there wasn't any hint of acetylene at all coming out of the tip.

Cap-n-Cray: Yes, that is the kit. I'm not using the cutting tip, just the brazing tip.

 

[Baby Grand]

Just my opinion ...

1)As Gary Fowler observed, remove & inspect the O-Rings for cracks, nips, tears, etc.
2)Regardless of the O-Rings condition, replace with fresh ones.
3)If you still see communication between the two sides, then pitch the torch and buy a good quality replacement.

Consider it cheap life insurance.

Jim

 

[BrentD]

I really don't think it's O-Rings as it's still cross-feeding with the tip removed and the control valves off. There's got to be a crack somewhere in the torch body either at or before the control valves.

At this point I think I'm going to toss the torch and go pick up one at the local welding supplier. I don't mind Harbor Freights disposable tools when the worst that can happen is a motor burns out, a bearing wears out too fast or a wrench cams out, but in this case where the flaw is causing the mixing of flammable gases and creating a situation that could prove extremely dangerous, I'm not going to trust my life to it. Further I feel like I should do something more than just toss the torch. This flaw is pretty serious and needs to be reported to somebody.

 

[Cap-n-Cray]

A torch body is not that complicated. It is just two adjusting valves that flow gasses to the tip. Has the torch body been damaged? If the torch body is crossing gasses then as Jim said pitch it or return it. Something is missing?

Be sure not to mix Oxygen with any oil. That is not good and can explode.

Cary

 

[Lazy]

 

[DanD78]

When you buy the new torch head get one with check valves built in or buy check valves to protect your self. They go in line on each hose.

Dan