stuck pipe

[scottsdad]

i have marti9n houses on telescoping pole like top rail well i have two peices that are stuck together dont know how guess rust even tho its galvenised can't drive them apart with a hammer tried to put penetrating oil down between them also tried heat with propane torch and twisting with pipe wrench any suggestions would be appreciated two pieces are about 5' long

 

[Puddles]

Try a #12 rose bud on a oxygen acetylene torch, get the outside pipe hot as you can, then shoot a CO2 fire extinguisher inside the other pipe.

 

[JOB]

When heating a bearing race or the pipe as your problem is. The outside pipe needs to get hot fast, if you heat it slowly the inside pipe will get hot and expand also and nothing will budge. If the larger pipe is open on the end put another smaller pipe in that end and try to drive out the first small pipe. If you have co2 try Puddles method.

I recently removed a shrink fit coupling from a 8" shaft. the coupling was heated with two propane weed burners. We did not check temperature on the coupling when we removed it but it was driven off the entire way. when it was put back on the coupling was heated to 350 degrees and went on with a lot of clearance. The inside material needs to be as cold as possible.

 

[Puddles]

In the past I've submerged couplings in hot oil, and packed the shaft in dry ice, and pore rubbing alcohol over the dry ice.

 

[JOB]

This shaft assembly weighted 1800 pounds, I don't
know how we could have packed it in dry ice. I
guess anything is possible. The coupling weighed
enough that two men could not pick it up. To put
it back on the shaft we picked it with an overhead
crane and hung it level and plumb with the shaft
while heating so it would slide on. This shaft is
turned by a 1750 horse power electric motor
spinning 750 R.P.M.

I worked on a smaller shaft some years ago where
the shaft may have been five inches in diameter.
To remove it we used two #15 tips on two oxygen/
acetylene rigs. One tip could not heat the
coupling fast enough and the shaft got hot also.
To put the coupling back on it was put it a oven
that maintained 375 degrees all day. That coupling
had to be carried up two flights of stairs and a
couple of hundred feet to be slid on the shaft
outside when it was -20 degrees. That one a man
could carry, but I don't think oil would have
helped. May have hindered a little.

 

[Puddles]

One of my son-n-laws gets to change the shafts in these things. I would love to see it done, but the Navy doesn't like visitors! :roll:

http://en.wikipedia.org/wiki/Ohio-class_submarine