3/4 to 1/2 inch reducers - are these required at both sides of radiators?

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Hi all

Am installing TRVs.

Some of the old rads need 3/4-to-1/2 inch tail 'reducers' to accommodate the 1/2 inch TRVs.

Question is, do I also need to reduce the outlet/lockshield valve end, or can I maintain the 3/4 inch valve on that side of the rads?

Thanks all!
 
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Am I right in thinking you have 3/4” nuts? If so, it might be that you have 1/2” tails, thus not needing reducers. As per @Exedon a photo may help.
 
This (in red) is the 3/4 inch tail. The TRV only accepts a 1/2 inch/15mm connection.

I was therefore going to buy this replacement reducer

Old valve (highlighted in orange), for info
 

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Just throw away existing rad tails and fit the ones supplied with trv strait into rad.
The problem with that is the pipework is a bit too tight and the new rad tails are longer than the old ones (see pic)!
 

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The female thread in the rad is 1/2". You will need to use the 1/2" to 15mm tails supplied with the TRVs. Looks to me as though there is plenty of room to fit them in. You may have to fit the tails, attach the valve then lift the rad slightly and lower the trv on to the pipe. If the tails are slightly too long, you can cut a few mm off the end. If the tails are too short, longer one can be bought separately.
 
The female thread in the rad is 1/2". You will need to use the 1/2" to 15mm tails supplied with the TRVs. Looks to me as though there is plenty of room to fit them in. You may have to fit the tails, attach the valve then lift the rad slightly and lower the trv on to the pipe. If the tails are slightly too long, you can cut a few mm off the end. If the tails are too short, longer one can be bought separately.
Thanks u, I had a similar thought re lifting it.

The lifting thing might work on one or two of the rads, but some of the pipework is far too tight on the others. The new tails are about 1cm longer, and I don't think it'll be possible.

I think replacement tails (with a very similar length) are the way to go, to stop me faffing too much
 

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Lockshield ends can be left the same. If new lockshields are needed, a plumbers merchant can supply ones with the same 3/4" union connection
 

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