Newbie wonders - "How, oh how?"

[GPG]

It all began with a suddenly leaking radiator 'tail'. 3 Leaks a) the drain c*ck (which happensto be there) b) feed (15mm) pipe to valve and c) Valve to ( it has an extension) radiator (at valve end).

Solved a) the drain c*ck had lost its washer. b) replaced the extension with an 'Oyster' thingy. c) In order to do b) I had to undo the valve-to-radiator connection at the other end. It was very tight, so the copper 'out' pipe - at 90' to the valve to radiator- gets bent; also when tightening it up again.

Question:- How do people prevent the 'at an angle such as 90'' get bent when one is using all one's force to undo or tighten the other connection connection? I ask because I'd quite like to remove all the radiators for flushing out, but I'm afraid of ending up with a dozen leaks at the copper compression joints. Besides, how tight is tight at the valve to radiator joints?

[Paul Worsley]

Large pair of grips on the valve, spanner on the nut.

In needs to be tight, but not strangled.

[Harry Bloomfield]

It happens that GPG formulated :

A spanner, self-grip, or even Stilsons placed on the valve, whilst another spanner is used on the connection. If necessary, put some rag under first to protect the finish. Pull on one and push on the other.

They need be no tighter than what is needed to provide a seal. Just nip them up gently, then a bit more if their is a leak.

[GPG]

Thanks for this advice. Looks as though the joints with olives are damaged because, the more I tighten them, the worse the seepage becomes. Not exactly leaks - I have to run a very dry finger along the top and bottom interfaces to find that they are damp. But I guess that that is not satisfactory. Back to the drawing board? I think I got an exagerated idea of how tight was tight because it was pretty hard to undo some of them in the first place - PLUS, I always believed that the length of a spanner was designed such that the average person would not be far out if he/she used reasonable force when tightening. I wonder if anybody has used a torque wrench in any of these plumbing situations and recorded them so that we could benefit from such data?

[Dave Plowman (News)]

This is roughly true of high tensile nuts and bolts.

FWIW, I'd take the fitting apart and clean it all with wire wool, then apply some Fernox silicone sealant which you'll get from a PM. Wonderful stuff.

It's possible you've got a deep scratch on the pipe running under the olive - or some damage on the tapered faces of the nuts. Either way I'd bet the Fernox will sort it.