Drayton TRV3 to TRV4 Conversion Heads

[squintnose]

I need to update some radiator valves in the house and currently have a mixture of Drayton TRV3 (I think) and Drayton TRV4's. The Type 3 has a plastic insert onto which the head screws, but it is very vunerable to knocks hence the need to replace.
I read somewhere that Drayton do/did a conversion head for TRV3 to make them TRV4. The Internet has a few leads but nobody seems to have any pictures so I cannot be sure I'm going for the right thing. Has anybody used them, are they okay - and the all important question - who actually has them?
All help would be sincerely appreciated by this rank amateur.

 

[Burnerman]

I've never personally heard of a conversion head but the TRV4 can be fitted directly where the TRV3 used to be...it matches up perfectly with the piece that goes into the rad, and the incoming pipework with the original olive, so its a minimal fuss thing to change. John

 

[squintnose]

John,

Thanks for your reply. Recognise that the TRV4 is a straight replacement for the TRV3, but am trying to do this without having to dismantle anything. This conversion valve is actually called a TRV 4c.

Regards

 

[teesph]

The t4 replacement head won't fit the t3. You need a t4c and they cost
about £25 + . The new T4 has a larger threaded diameter ring than the
t3.

good luck