How can I replace 1/2" TRVs with existing 3/4" tails

[grumpyproger]

Hi I am a homeowner/DIYer albeit reasonably confident, so I may not be using right terminology etc, but here goes:

I wonder if you can help! I want to replace my rad valves to the TRV type and locksheild, but I have a problem. The tails currently on my rads are the larger type (3/4")! the Pegler Terrier valves require the smaller tail (1/2"). My question is, "If I remove the existing tail can I replace it with a chrome BSP 3/4 male x 1/2 female reducer and then insert the tail that comes with the Pegler TRV. Is it possible and is it safe !! or am I being a silly billy!!!

Any comments gratefully received

 

[ShaunCorbs]

It will be 1/2 into the rad you need to remove the tail coming out of the rad and replace it with the new one what comes with the trv

(Don't forget to add ptfe to the tail threads before you tighten it into the rad)

 

[townfanjon]

You will be better using loctite 55 rather than ptfe , a few vids on you-tube on how to use it

 

[ShaunCorbs]

You will be better using loctite 55 rather than ptfe , a few vids on you-tube on how to use it

Or 577 but most places don't stock it

 

[Old Account]

if you drained the system don't forget to put inhibitor inside the system like sentinel x100.

But agree with above comments, both will work ptfe and loctite. I always use loctite it's the better stuff for me personally.

 

[grumpyproger]

It will be 1/2 into the rad you need to remove the tail coming out of the rad and replace it with the new one what comes with the trv

(Don't forget to add ptfe to the tail threads before you tighten it into the rad)

Thanks for that ShaunCorbs, just for me to be sure are you saying that I will not require the reducer, I think the diameter of opening on rad will be to large to accept 1/2"!

 

[Old Account]

Thanks for that ShaunCorbs, just for me to be sure are you saying that I will not require the reducer, I think the diameter of opening on rad will be to large to accept 1/2"!

Have you got any pictures?

 

[grumpyproger]

Thank you for responses so far, I will def put an inhibitor in the system, but I had no idea I could use loctite rather than ptfe tape. Many thanks

 

[Old Account]

Thank you for responses so far, I will def put an inhibitor in the system, but I had no idea I could use loctite rather than ptfe tape. Many thanks

You can use both either ptfe like ShaunCorbs has mentioned or loctite. Me personally I prefer the loctite but that's just the preference.

 

[ShaunCorbs]

No it shouldn't (stnd rad is normally 1/2) but post a pic up of the lockshield valve in question

 

[Darren Jackson]

The old tail in the rad will be a 1/2" thread with a 3/4" nut. So you just need to remove it with a radiator allen key or spanner and simply fit the new 1/2" tail which will have a 15mm compression to fit the TRV. No other fittings are required like reducers. Apart from PTFE & X100 that's it my friend, but make sure you wrap the PTFE the right way round or else it will just undo itself as you tighten up the thread Good luck.