Hello. Just after a bit of help and advice. I'm changing a couple of radiators in our house and also putting in new TRV's. The new radiators are slightly shorter than the existing ones so I am planning on using TRV extension pieces at either end. The parts have arrived today from Screwfix but i'm not sure about something. (Please forgive my ignorance from this point on!) The extension pieces i've got our the rigid type rather than the telescopic.
The TRV's look like this:
The problem is that the 15mm pipe bit of the extension doesn't appear to fit in the TRV. The nut does obviously fit but should I not expect the pipe to slot in to the TRV rather than just butt up to it? Do i need something like this?
plumbuniverse.co.uk
Hope that makes sense!
https://www.NoLinkingToThis/p/tesla...rc=aw.ds#product_additional_details_container
The TRV's look like this:
https://www.NoLinkingToThis/p/nickel-angled-radiator-valve-lockshield-15mm-x/39238
The problem is that the 15mm pipe bit of the extension doesn't appear to fit in the TRV. The nut does obviously fit but should I not expect the pipe to slot in to the TRV rather than just butt up to it? Do i need something like this?

Buy 15mm X 3/4" BSP Radiator Valve Connector Piece 15mm X 3/4" Chrome Union Nut at Plumb Universe, Plumbing Store
Welcome to Plumb Universe, the No1 online shop to purchase 15mm X 3/4" BSP Radiator Valve Connector Piece 15mm X 3/4" Chrome Union Nut at the best price.

Hope that makes sense!