flexible piping

[daroberts77]

I wish to replace a radiator valve with a thermostatic one. The TRV is 2 cm longer than the existing valve. The inlet copper pipe is set in concrete. I have cut the copper pipe near the floor and have put in an 8 cm piece of brown plastic pipe but I cannot get a watertight seal between the valve and the plastic pipe. Is there a more flexible pipe I can use?
daroberts77.

 

[wiggikins]

Can't make head nor tail what you are asking, can you be more specific?

 

[JPC]

 

[daroberts77]

Hi wiggikins, The existing copper pipe feeding a radiator is set in cement and has no flexibility. I am replacing the inlet valve with a Myson thermostatic valve. The overall width of the Myson is 2 cm more than the old valve. In order to gain some flexibility I cut the 1/2" copper pipe near the floor and used a piece of plastic pipe 8 cm long. However, I cannot get enough flexibility on the plastic pipe and it is going into the Myson valve at a slight angle. I have used plenty of PTFE tape on it but I am still getting a leak between the plastic pipe and the inlet to the valve. Is there a type of pipe I can get to solve the problem?

 

[numpty1]

have you used an insert.easiest way is go to the plumbers merchant and ask for an extended rad tail.

 

[ChrisR]

Other way, numpt. The TRV is always longer than the older superior union design. Bluddy nuisance.
Often you can cut a cm or so off the end of the 15mm spigot on the radiator insert, but that's going to be difficult if you can't get the olive off.

It looks too solid to cut with a pipeslilce but it works with an adjustable pipe cutter if you go gradually.

If you're stuck with it you might be able to use one of these
http://www.screwfix.com/prods/15531...es/Adjustable-Radiator-Valve-Tail-Compression
You can cut the pipey bit they supply if necessary, and slide the rest right into the radiator, so you can get the nut on your valve hard against the part in the rad.

 

[numpty1]

chris i know what your saying a swift sharp boot on the side of the rad will give you 1cm and your method of triming the tail will give another 1cm,make the tail into the rad and use a jnr then tap the olive up tight into the nut,being in ireland the pipework will have 9mm lagging chop a bit out of the floor around the pipe and manipulate the pipe to suit.bit late now he only has a short stub to deal with

 

[ChrisR]

Can someone tell me why they don't make TRVs with proper traditional unions so you don't have to bend the pipe out of the way to lift the rad off?

Wouldn't even need to be a 3/4 union - the hole in a TRV is only about 5mm!

 

[Norcon]

Yes the boot method works.
Cutting the copper off at the floor was a big mistake.

 

[wiggikins]

Bending machine+ make a bend in rigid pipe like we had to do years ago