microbore connection

[cgm1971]

i am trying to fit a 8mm microbore to a radiator valve i have the reducer (Brass ) and it slides on and off the end of the micro bore pipe even when tighten. how do i fix this so it doesn't slide off

[Dave Plowman (News)]

Unless you've missed out the olive, it's not 8mm.

[Lobster]

(but you don't need an olive if you have a reducer??)

I'm guessing you have a reducer for 10mm microbore. It should be a very snug fit before tightening up the compression fitting. If it's definitely an 8mm reducer, then you aren't tightening it up enough)

David

[Dave Plowman (News)]

If it clamps onto pipe how would it work without?

[Lobster]

Cos it's a kind of 'self-olive'... assuming this is the kind of thing:

When you tighten them up you hear a slight crack as they snap into two inside the fitting (at the point where there's a deep groove, near the close end of the pic), and the two bits (I think) then mate together as you continue tightening the nut. Certainly the small bit gets compressed down like an olive.

I fitted several of these last week, but haven't dismantled any to investigate exactly how they work - and that's a good thing as it means they all sealed fine!

David

[Lurch]

On 1 Apr 2007 08:32:26 -0700, " [e-mail]" mused:

If the reducer is the one that came with the valve then it's most likely a 10mm reducer. You need to either source a 10x8 reducer and alter the pipework before it gets to the valve or find a reducer for the valve that takes it down to 8mm.

If you have already tightened the assembly to a suitable tightness then the reducer may well be unusable now anyway as it deforms internally to tighten onto the pipe.

The other reason it might not have worked is that you are a girl and your weak limbs aren't capable of tightening the thing up properly. ;)

[Dave Plowman (News)]

Ah - not used or seen that type. The ones I've used have just been like a conventional compression fitting. Although I'd more usually prefer solder fittings.

[fred]

In article , Dave Plowman (News) writes

The reducing sets I have used for compression fittings certainly use an olive but I'm sure others have mentioned a sort of pre-assembled (and less fiddly) one-piece.