compression joints

[dazzlerpalmer]

50% of the new rads I have fitted are leaking on the unions to the valves.

I was under the impression that as long as they are clean and well lined up no paste/gear is needed, you just connected up and tighten.

I got the rads from Plumbworld and the valves are Danfloss TRV.

p.s. they only weep when cold, when hot they appear to be ok

Thanks Awfully

 

[kevplumb]

joint in accordance with the above
instructions, a slight weep is experienced – as
may occasionally happen – it will be readily
corrected by the application of a smear of an
approved compound to the sealing faces.

from the kuterlite instructions

 

[dazzlerpalmer]

thanks for that - whats the best stuff.

I have used stuff in a pot that really does not keep well. (looked a bit like putty). I once saw a plumber use something from a tube but forgot to ask him what it was

 

[numpty with a crowbar]

Plenty of pipe jointing compounds out there.... Take yer pick I've used Boss Green pipe jointing compound myself and that's fine so far - give the threads a nice smearing and you're laughing.
If I were you I'd buy the green one rather than the red - the green is suitable for potable water but the red ain't - the red's cheaper but if you ever need to use it on drinking water you can't, where as AFAIK the green can be used ok on non-drinking water apps such as rads...

*Probably wrong though*

 

[Nige F]

thanks for that - whats the best stuff.

I have used stuff in a pot that really does not keep well. (looked a bit like putty). I once saw a plumber use something from a tube but forgot to ask him what it was

......................Pot= Boss white, goes off , thats how BSS made their fortune (British Steam Specialities)..then took over PTS TUBE = Fernox LSX still goes off in the cap better but dearer..........Engineers make flange joints dry Then look down on plumbers BOSS RED must be for oil jointing ( red hermetite?)

 

[kevplumb]

I've used Boss Green pipe jointing compound myself and that's fine so far - give the threads a nice smearing and you're laughing.

does no good whatsoever on a compression joint

 

[bripl]

best stuff jet blue from plumbcentre gas/air/water/steam/potable water one smear on the olive tighten up nut never to weep again,unlike dereck the diyer

 

[Paul Barker]

ditto to jet blue. Obviously applied to olive not thread.

Boss white better still and perfectly alright on heating, and much more manageable than boss green. Obviously can't use it on potable.ctually

I had a Ship's Engineer nearing retirement working for me for a while. He did all his joints up dry. If the pipe is unblemished and you use copper olives and have the technique it is true you don't need paste. But seldom do those three
conditions meet in one place at one time. He was good at compression joints though. I believe it's vertually all compression on ship, and if anyone saw you with paste they'd say "what's that?" and throw it over the side. That's what he said anyway. Actually he was very useful allround, quite worthwhile having someone who approaches our trade from a different but equally if not better qualified perspective. One of the things I picked up from him was to use shifters more and grips less. He was quite right, we plumbers tend to try and do everything with our grips except rad valves which we musn't blemish, but you get a much better feel for a compression fitting bighting if you use a shifter.

 

[bripl]

when the joint is dry,tighten with 10inch shifters till it screams

 

[dazzlerpalmer]

I knew there was a problem when I was leaning on the spanner with a lump of scaffold pole - red in the face with a possible hernia and me nuts round me ankles!

Still didn't stop the b*d leak

I'll smear a bit of gear (jetblue) on the olive next time.

cheers