Why TRVs com with rad tails?

[JohnArnoldBrown]

Is there a reason why TRVs all seem to come with radiator tails?
It seems it would be much quicker to replace an existing valve using the existing tail. Same goes for the olive and nut on the pipework, although I can see how a pre-used olive might cause problems. Is it because the flange type joints aren't standardized?

 

[Dan Robinson]

What happens when you fit a new radiator?

What if the existing tail is three quarter inch?


Is this a wind up?

 

[stardanny]

You still need new radiator tails for new heating system.

Daniel.

 

[jeff the gasman]

The flange joints were available some years ago on TRVs
I think they were Giannoni valves if I remember correctly.
Haven't seen them for ages.
Jeff
Edit
Danfoss commercial valves are with union.

 

[JohnArnoldBrown]

"Is this a wind up?"
No.

Maybe I should rephrase.
If I want to fit TRVs on existing radiators that already have tails, and the flange size/thread on the TRV matches the rad tail, is it still advisable to change the tails?

 

[jeff the gasman]

No. Just use a little jointing paste.
Jeff

 

[JohnArnoldBrown]

Thanks.