TRV compression joint

[wilgartw]

I have a house with an old central heating system but new boiler. I have removed one of the radiators to decorate, the radiator has an old trv which connects using a 3/4” tail. When I came to connect it all back up there were leaks from the inlet copper pipe to trv body connection. On closer inspection the olive was mangled. I removed the olive but then struggled to get another on because the pipe was linked and bulging. I cut the piece closer to the floor and went to join the pipes to find out the pipes are imperial. A quick run to screwfix for a 1/2” to 15mm coupler. Ready to go.

But here is the issue. The connector for the bottom of the trv body has a compression joint, but the nut is male not female, there is no chamfer on it for the olive, and it doesn’t allow the olive to move down the pipe. When I tighten the olive it never fully tightens as the olive as overhangs the end of the copper pipe.

Am I missing something really obvious, but it doesn’t seem like a standard olive is the correct sealer. What do I need?

 

[kidgreen61]

I'm fairly sure that is, as you say, a mangled olive, it isn't far enough on the pipe, I would pull/cut it off, and put a new olive on.
You may find it helps if you nip up the new olive, then separate the joint,wrap a couple of turns of PTFE tape around new olive to ensure a watertight seal.

 

[wilgartw]

That is my third attempt. The pipe doesn’t go into the fitting further than the olive so every time the olive bends around the top of the pipe. I will try nipping the olive before tightening, but I cannot help thinking this is not the correct part for the job.

 

[terryplumb]

Can you show us pics of the inside view of the valves inlet ,and the mating surface of the male threaded part ( without olive) .
And the ORIGINAL copper pipe end, if you still have it.

 

[terryplumb]

I suspect it's a type B , manipulative fitting .

 

[wilgartw]

This is the original olive and the top of the pipe. I cut the pipe directly below the olive

 

[terryplumb]

It's a type B ,and someone has shoved an olive on . It's pure luck it didn't leak originally.

 

[wilgartw]

This is the male thread, as you can see there is no chamfer on the end.

Then the female trv body. The male thread goes the full length of the female.

 

[wilgartw]

Do what is a type B? What do I need to do to make it seal?

 

[terryplumb]

Is the valve tail that is threaded into the radiator a half inch BSP THREAD,if it is fit a complete new valve.
That type of joint requires the male threaded part to be put onto the pipe ,and the copper pipe end is flared over ( so the threaded part can't come off) .The seal is made by the flared copper pipe end being compressed when the joint is tightened up.

 

[wilgartw]

so is it a DIY job? can I buy a flarer? is it going to be cheaper to buy a new radiator tails and TRV?

 

[terryplumb]

Buy a new valve ,if your tail thread is half inch . It takes a bit of skill ,even if you have the tools to do it.

 

[wilgartw]

the tail thread is 3/4". this was the only TRV body I could buy that had a 3/4 inch connector to the radiator. I guess I can replace the tail, but then I need to get the old one out. that is a different issue. it doesn't have a hex key to remove it, it has two lugs.

 

[wilgartw]

 

[terryplumb]

What valve have you bought ??
Your pic shows the union to the valve ,which may be 3/4, but the thread that goes into the radiator ( the tail) is possibly half inch.