Tight compression fitting

[Bogart]

Trying to get the 3 port valve off so I can get on with changing from Y plan to S plan. Problem is one of the compression treads will not come free. And being sods law it is the one feeding into the DHW tank. Have tried brute force with 2 large spanners, tried heating it, and freezing it and penetrating oil. I do not want to use extensions on the spanners as when I use them now the joint into the DHW cylinder flexes!
Any others ideas gratefully excepted.

 

[steadyon]

Cut the pipe and then if necessary lengthen with a soldered coupler?

 

[exedon2]

Why not undo the cylinder union then take lot out? Cut pipework as needed as your altering anyway. A gentle tap with hammer works wonders!

 

[Bogart]

Thanks for the prompt replies. The offending nut is B in the attached photo. Am loathe to try to undo the cylinder connection, A, as the locking ring is buried deep in the foam insulation and I have fears if it is tight I could break the cylinder connection.

 

[Bogart]

Cut the pipe and then if necessary lengthen with a soldered coupler?

Hopefully as you see from the photo there is not a lot of scope to cut the copper pipe.

 

[Bogart]

What I may resort to is grinding the nut off.

 

[ShaunCorbs]

It will come off try tighten it a smidge then Undo

 

[exedon2]

Take head off valve so you can get some grips on it to hold against yourself

 

[Bogart]

Take head off valve so you can get some grips on it to hold against yourself

Tried that as much as possible. Ended up grinding it off, is nothing simple. Am amazed top exit did not leak as O ring was loose, very loose. Managed to slide it off the pipework by hand. Can only think the copious amount of Boss White that had been applied, by original installer, was doing a good job.