Replacing radiator valves - having problem with new valve tails

[ziggy]

Folks,I feel really dumb asking this question ... but here goes:Just bought a load of new radiator valves and lockshields to replace the old valves on my old system, and I cannot work out how the supplied tails work.My old valves are 3/4" BSP and the tails are designed so that the nut which connects to the valve is captive so it is a simple matter of installing the tail into the radiator and then tightening the nut onto the valve.The new valves just have 15mm compression connections on them (that would accept 15mm pipe with olives) and the supplied tail has a 1/2" BSP thread on one end (that goes into the radiator body) and a short length of chrome pipe on the other end. The chrome pipe end gladly accepts an olive and slots into the compression connection on the valve, but when I hand-tighten the compression joint it does not "grip" the chrome pipe whatsoever ... it just spins around and can be easily slid out of the compression joint altogether without even removing the nut!I am sure I am missing something glaringly obvious here ... so please be gentle with me!I haven't tried tightening up the compression joint yet with a wrench (only tried it hand tight) as I don't want to go at it with brute force if I am barking up the wrong tree!Any help would be much appreciated.RegardsZiggy

 

[hihowudoin]

unless you have the grip of a bear then you are not going to "compress" the olive onto the pipe, therefore the use of spanners is recomended. obviously tweak the nuts up but don't make the olive scream. good luck.

 

[royston]

as said sounds like some spanners are required. If you have any ptfe tape to hand, a couple of raps round the olives will help seal.

 

[Kevgas1]

Is the olive brass if so try swapping for a copper one , also try roughing the chrome with sand paper

 

[ziggy]

Thanks folks, Don't have my tools here with me so can't try tonight.I just thought that even hand-tight I would feel some sort of light grip ... but maybe I over-estimated my own strength ... or I'm getting weaker as I get older!The olive is brass so maybe is a bit more resistent than a copper one?I guess I shouldn't worry anymore i.e. once I get a spanner onto it things will work out just fine. If not, I will try out some of your other recommendations.Thanks for all the info, you folks are a real help.Ziggy

 

[Blackcatgas]

As said, you wont get the olive (cone) to grip the pipe with just hand tightness, youve really got to give them a good nip up with spanners, dont over tighten though, with exp you get a "feel" for how tight to thighten (sp) a compression fitting.

 

[ziggy]

Thanks for the help folks ... I was overestimating my own strength! Just a small turn with the wrench and it stayed firm ... now I have no excuses not to do the job ... BAH!