New Radiator Tail - How tight should it be ?

4 Jan 2008
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United Kingdom

I am in the process of fitting new TRVs to my radiators.

I removed the old radiator tails and was surprised how much force it took to remove some of them even when using the correct sized spanner.

I am planning to install the new radiator tails using Loctite 55.

I understand that the radiator tails are a tapered thread.

Does this type of thread bottom out and go tight the tail is fully installed ?

If so do I simply gently nip it up at this point as this will be tight enough ?

Many thanks in advance.
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Tails are taper but often rads are parallel. So often do go in a long way.
How tight? Well that (grunt!) and a bit more!:whistle:
Unless you are superman you will not over tighten a tail-piece into a steel rad (copper or alli might be a bit more fragile) if you are using say an 8 inch spanner or one with a Tommy bar just as tight as you can comfortably one handed. (y)
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I always use traditional PTFE tape but they do surprise people by needing about 10 turns.

When they are the type with a hex socket then about as tight as you can get them with the standard Allen key sold for the purpose.

If the one with four flats then pretty tight if using a 200 mm adjustable.


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