Separating rusted Galvanized Steel Union?

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  #1  
Old 12-12-16, 10:19 AM
J
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Separating rusted Galvanized Steel Union?

I have a long length of 3/4" galvanized pipe which has been buried for a few decades. As you might expect, it has a light layer of rust on the outside.

I want to separate and remove a union WITHOUT messing up the pipe's threads, so I can thread either a new union or coupling on that pipe. My plan is to use a lot of PBlaster on the connection and let it soak for 24 hours, then repeat, then use two big assed pipe wrenches on it.

Anyone know of a better technique for removing the union while leaving the threads usable? I used conventional gray pipe joint compound on the fitting 30 years ago; no Teflon tape or modern white Rectoseal compound.
 
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Old 12-12-16, 10:42 AM
C
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Heating the fitting (not the pipe) may help as well. But I would have a plan B in mind in case the pipe has rusted from the inside and just crumbles when you try to remove the union.
 
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Old 12-13-16, 07:37 AM
J
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If it was mine I'd be spending my time digging it all up and replacing with some form of plastic pipe.
Steel pipe will rust out from the inside out 100% or the time even under the best of conditions like inside a home.
You'll have rusting issues on the inside and the outside.
First thing I do when buying a home that has steel plumbing is figure out what it's going to cost to replace it and take that amount off the asking price.
 
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Old 12-13-16, 04:27 PM
M
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I agree with Joe, it would be better to tear out the galvanized and replace with PVC.
 
 

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