need help removing stopcock nuts on pipe

nptes

hi i am in the middle of replacing my internal stopcock under the sink but got as far as taking it off and finding that the nuts on the pipes do not come off.
how can i get them off without removing the pipe to fit new ones ?
regards

ormus

you can saw them off. but why?
how are you going to fit the new 15mm ones? does the pipe have olives, or has it got swaged ends?
better just to cut a section of pipe out and replace it, complete with the new stopcock.

Ebe_Scrooge

You could try the old trick of tightening the nuts a fraction before undoing them - this sometimes loosens the seal. Another option is heating it with a blowlamp, again the intention being to break the seal due to expansion. Couple of problems with this - ideally you want to drain the pipe first to make it more effective, which can be a pain. Also, it's a bit dodgy mucking about with a blowlamp in a confined area, especially if there's wooden cabinets nearby !

Failing that, as a last resort, cut it off with a hacksaw and fit new compression fittings with the new stopcock. The BIG problem with this is that you may find the new stopcock is shorter that the gap you're left with, which means an awful lot of fiddling around to sort it all out. So think and measure VERY carefully before taking this option !

nptes

i need to fit new ones which came with the stopcock, because i tried using the existing ones but the bottom one leaks badly.
how do the nuts stay on the pipe? and how will the new ones stay there?

not sure what 'swaged ends' means but the new nuts have olives.
thanks

27col

You have several options.
1) You might find that the existing nuts will fit onto the new stopcock. This assumes that it is the same length as the old one.
2) Cut the pipe and fit a new section containing the new stopcock. As per ormus post.
3) Gently saw the old olive off with a junior hacksaw. This assumes that you can get good access.
4) Use an olive puller. These are a bit expensive just for the odd job. http://www.toolstation.com/documents/search/index.html
5) Don't bother to remove the old stopcock. Just insert a new one elsewhere in the main.

Ebe_Scrooge

The stay on the pipes because of the olive. Basically, when you tighten up the nut onto the threaded stopcock, the olive gets squashed down onto the pipe, creating a watertight seal ( the olive is very soft copper ). To remove the old ones can be a bit of a fiddle - you need to undo the nut, slide it back out of the way, then you should see the old olive squished onto the pipe. You need to remove this before the old nut will slide past it and off the pipe. To remove it, grab it with a pair of pliers and rotate it around the pipe. It should eventually loosen up and you can slide it off. Be careful not too use too much force else you'll twist the actual pipe and disturb other joints further along. It's best to support the pipe with another pair of pliers, or similar, to stop it moving whilst you're twisting the olive.

Once you've got the old one off, it's dead easy to put the new one on. Before you put the new one on, it's well worth giving the pipe a really good clean with fine emery and / or steel wool until it's clean and shiny - this will ensure you get a good watertight seal with the new one.

Finally, if you do fit it then find it leaks, you'll need to fit a new olive when you come to re-fit it. They only cost pennies from any hardware barn, just get the right size ( usually 15mm or 22mm are the standard sizes ).

nptes

thanks scrooge, real big help. i will try that.