Un-Threading Brass in Brass Pipe Threads

[Tractor Seabee]

I'm have reached an impasse trying to unthread a non-operative brass gauge from the brass housing of an oxygen regulator. First it is doubly difficult as there is not a good way to mount such gauges in a vise. It is a 1/4" pipe thread. I have used several type penetrating oil and as mush force as a 9/16 wrench with a cheater pipe with no yield. They must make these up dry and distort the threads.

Anyone have any bright ideas short of drilling it and rethreading? Barring any workable ideas that is my last resort. I am at my wits end with this. The regulator is Harris and worth fixing. Over the years I have replaced a lot of these gauges on regulators.

Ron

 

[ultrarunner]

Anyway to use heat/cold to persuade?

 

[CoyPatton]

As I understand your description you have brass on brass. These fo not corrode. Unfortunately, I have experienced people doing many crazy things to create a seal on the threads.
Some of the worst for future removal is red thread lock. If this is the case heat is the only thing I know to suggest to break that bond. It will need to get pretty hot and may need more than 1 heat cycle.
Another one us over tightening the joint. Sometimes these can be loosened with either a vice, using 2 wrenches (pipe wrenches) with cheaters. Heat application may also help.

 

[WranglerX]

IF regulator body has large hex area on back side it is for actually mount body in vice.... Was informed of this by repair shop....

If you can anchor regulator body you can deal with gauge easier....

Gauge is probably over tightened, they spin them down to a point tapered thread do not leak and gauge faces correct way.... My regulators did not have thread locker but had devil of a time to change the tank connector on acetylene regulator...

Or....

Regulator and Torch Exchange, Inc. Regulator and torch repair, parts, and service.

These people supplied new diaphragm kits for my Victor regulators, and when I got stuck they answered my email questions........

Dale

 

[Tractor Seabee]

Anyway to use heat/cold to persuade?

Not a good idea due to the internals of the regulator especially the diaphragm.

Ron

 

[ultrarunner]

I was thinking the diaphragm, etc. would be out with just the shell left...

Dry Ice has saved me a few times and having free access to it helps.

 

[Tractor Seabee]

I was thinking the diaphragm, etc. would be out with just the shell left...

Dry Ice has saved me a few times and having free access to it helps.

That is an idea. Have to shrink just the base of the gauge as freezing the body would make it shrink and get worse, but maybe freeze and thaw several times. I will get some dry ice tomorrow. Makes me think, I have a cylinder of CO2, turn upside down and you get liquid.

Ron

 

[denchen]

Put it in the freezer in the house over night. In the morning, put a right size spanner in boiling water and let it get as hot as you can hold with a rag. When your ready get the thing in the vice as quick as you can, then a good steady pressure using you hot spanner. Good luck.

 

[WranglerX]

Put it in the freezer in the house over night. In the morning, put a right size spanner in boiling water and let it get as hot as you can hold with a rag. When your ready get the thing in the vice as quick as you can, then a good steady pressure using you hot spanner. Good luck.

Think you concept of how expansion and contraction of heat and cold is backwards to the actual science....

Dale

 

[Smokeydog]

Careful. Oxygen and oil don’t mix. Explosive combination. Maybe why no thread sealant was used and tightened securely. Once you have used oil it is difficult to clean.
Thermocycling might work. They make a can spray that cools to break connections.
Be sure to use oxygen specific gauges.
Local welding supply could tell you if your regulator is worth rebuilding or replacing. May give tips on how they replaces gauges. They can rebuild torch seals too.
Sadly a lot of cheaply made sets now aren’t worth maintaining. Even some quality brands have cheap sets to compete. Smith brand use to give lifetime warranty. You can readily see and feel the difference of quality regular and gauges made to be serviced. You have the smarts and experience to make good decisions.

 

[CoyPatton]

Not a good idea due to the internals of the regulator especially the diaphragm.

Ron

Totally agree, but when it is useless in current state, do you replace some parts or trash everything?

 

[WranglerX]

Totally agree, but when it is useless in current state, do you replace some parts or trash everything?

Due to the nature of the beast and implication if it goes wrong, I would send it in to have qualified technicians do the work...

Dale

 

[Tractor Seabee]

Minimum price here for repairs to regulators is $70 plus 10% tax. Talked to their repair guy and he stated some of the treads are very difficult unless you have a special vice for holding regulators. Also they do not recommend repairing other than the high end ones. The little guy is priced out of the high end market with all the knock offs around. I can buy used name brand regulators cheaper than the repair. My time is my own so I may just drill it out. Tried all the thermal shock ideas you guys have to no avail. I am well aware of the oil situation, use only non oil sealants. Thans all for your ideas.

Ron

 

[bcp]

Vibration sometimes helps. I would try an air ratchet with a crowfoot wrench. Don't let it rotate, but apply enough force to stall it in one position.

Bruce

 

[ultrarunner]

Im pulling for you...

When I had trouble changing out regulator oxygen fitting to tank a retired gas plant guy said to screw it in tight to the large cylinder first so as to use the cylinder as my vise.... it work and avoided visegrip marks on the brass

 

[FarmaBro]

Could it be... wait for it... left hand thread? Are the hexes notched on the edges?

 

[WranglerX]

Could it be... wait for it... left hand thread? Are the hexes notched on the edges?

Probably not almost all US made gauge bodies use 1/4 inch NPT.... Even the acetylene body is 1/4 inch pipe thread, it just uses a nipple on outlet that is 1/4 inch NPT on one end and 9/16 X 18 UNF LEFT HAND thread for hose connect...

Dale