Presto-Lite torch rebuild

[chucketn]

I am in the process of rebuilding my Prest-O-Lite Acetylene(originally Union Carbide) torch. It’s 60 or so years old, inherited from myDad. The o-rings in the valves have all hardened and the 401 handle leaks gasaround the valve stem. I have ordered the proper o-rings from WeldingSupply.comas per the original instructions/parts list from Prest-O-Lite. I tried o-ringsfrom a kit from HF with no joy.

My question, should I use some type of lube on the newo-rings when I install them?

Chuck

 

[moya034]

Well as we all should know it's a fact you should never use oil or grease of any kind on oxygen equipment or any modern gas apparatus.

That being said the old prest-o-lite torches are not modern and don't have oxygen running through them. Acetylene gets along with most non-metal things OK so I have to go out on a limb here and say it won't hurt anything, but I'm not an expert. As to whether or not it is advisable and warranted, I really don't know. I do see where it would lengthen the workable life of the o-ring.

I have one of these same torches, but it still seems to work good for me. I hope you can take some pics of your rebuild and post them here.

 

[Tin Falcon]

The only grease you can use with Oxygen lines is that I know of is DuPont krytox. It is synthetic not flammable and quite expensive. it is a mixture of krytox oil and teflon powder.

http://www.ebay.com/itm/DUPONT-KRYTOX-GPL-205-Grease-oz-SCUBA-Oxygen-Nitrox-/270726776495

McMaster Carr cat # 10195K19 $16.50 for 1/2 OZ.

Dupont aplication sheet here

http://www2.dupont.com/Lubricants/en_US/assets/downloads/new/K-15481-Oxygen-Chemical-Applicaton-Sell-Sheet.pdf
Tin

 

[chucketn]

The Prest-O-Lite torch is an acetelyne/Air torch. Is there a legitimate o-ring lube that can be used in this application?

Chuck

 

[Tin Falcon]

you are likely OK with a silicone grease but to SAFE check with presto lite or a welding supplier.
Krytox is rated for reactive gas so it would be safe .
Tin

 

[Septic]

On any equipment designed for dry seals I would NEVER risk using any product for that purpose... If your o-rings don't seal when dry, you really want to know why...

 

[Tin Falcon]

Septic has a good point . while krytox is non reactive these systems are designed for no oil. Follow manufacturers recommendations when in doubt.
Tin

 

[moya034]

I forgot to mention that I've been known to purchase a lot of used gas apparatus. I usually get my used stuff refurbished by the local welding shop. They do great work, it comes back looking brand new, and I've never spent more then 50 bucks on a piece for professional work.

 

[chucketn]

I have received and installed the proper O-rings for my Prest-O-Lite Acet/Air Torch. I’m pleased to say it no longer leaks around the shut off or needle valves.

Next question, does anyone know how to adjust the shut offvalve? I have the origional Prest-O-Lite/Union Carbide instructions for the 401Torch Handle but they aren’t very clear on setiing thes valves after replacingthe o-rings. Even with the shut off valve turned all the way in, the pilotvalve will open enough to get a small flame (pilot), but the shut off has no effect.

The problem is that the shut off valve handle is a set screwsecured collar on the valve body. The valve has a stop that prevents rotatingthe valve more than 360° so adjustment is a process of removing the outerhandle, adjusting the valve and reinstalling the outer handle to test.

I did not post pictures but here is a link the instructions I have.

http://www.google.com/url?sa=t&rct=j&q=prest-o-lite%20401%20instructions&source=web&cd=1&sqi=2&ved=0CCoQFjAA&url=http%3A%2F%2Fwww.esab.ca%2Fliterature%2FArchive%2FManual%2FF-9000%2520-%2520F-9499%2FF-9324-J_PREST-O-LITE_401_TORCH_HANDLE.pdf&ei=k6DZUejGO4r48wT_7IG4CA&usg=AFQjCNFMvFPZ4XJQfkU5UgvvemBwaUGmRA&bvm=bv.48705608,d.eWU

Chuck