Reducing internal compression coupler 15mm to 10mm

[cf-leeds]

Hi,

I'm about to change some radiator valves, which are getting old and will replace them with TRVs. I originally installed my heating with 10mm copper pipe.

So, the new TRVs which I've bought have single piece reducing compression couplers in them (15mm to 10mm). I'm totally unfamiliar with this type of coupler, as I installed my original valves with 3 piece compression reducers, which have held out fine over 20+ years.

I can find very little detail/illustration on this type of single piece reducing coupler. There seem to be no olives involved, so I'm assuming that you just slide in the pipe end and tighten up until something grips/seals the pipe ?

Can anyone advise on the reliability of this type of coupler, vs. the 3 piece version. Is it as reliable ? Should I throw them and use the 3 piece version ?

Any tips welcome.

Thanks in advance

[Fredxx]

Is there any reason why you didn't go for radiator valves suitable for

10mm bore pipes? You could re-use the olive and nut.

I would go for the 3 piece version as this uses a standard olive. However, if you go down this route you'll have to remove the old olive which can be a pain.

[cf-leeds]

Fredxx:>Is there any reason why you didn't go for radiator valves suitable for 10mm bore pipes? You could re-use the olive and nut.

I thought I'd actually ordered 10mm valves from Screwfix, but I now see that they're just 15mm valves with adaptors. I don't mind using an adaptor, but just want to use the best option.

[The Natural Philosopher]

God help you then.

[Fredxx]

10mm is fine where a manifold is used and a relatively short final lengths of 10mm are used to the radiators.

You obviously have never had a central heating system with legs done in

10mm.

Personally I would install a backbone in 22mm and dedicated lengths to rads in 15mm.

[RJH]

Yes, I did that at my last place, then 15mm-10mm for the last metre or so. Much easier to route the 10mm pipe behind skirting boards etc.

[SteveW]

My parents' system, installed in 1972, used 22mm copper to and from the manifolds and 12mm, 10mm, 8mm and even 6mm (!) plastic pipe to the radiators. There were no balancing valves, with all radiator sizes, pipe lengths and sizes calculated to build a pre-balanced system. Single panel radiators all had both pipes to the valve at one end, with an internal pipe running the hot feed from the valve to the far end of the radiator, while doubles simply had an elbow at the far end for the return.

It worked well for decades, but eventually the plastic pipes became brittle and far too easy to break, so it was all replaced with larger copper pipe and standard valving.