One piece/three piece compression reducers

[qwertyb]

Are these https://www.plumbcenter.co.uk/product/center-compression-one-piece-reducer-15-x-8mm-p543541/ or these https://www.bes.co.uk/15-mm-x-10-mm-reducing-set-dzr#product-details-tab a better option for fitting 15mmTRVs to 8mm and 10mm pipework rather than use soldered reducers?

If so, which is better - one piece or three piece?

 

[Dan Robinson]

One piece is better than 3 piece.

Soldered is better than anything compression.

 

[qwertyb]

The problem I have with soldering is the location of a couple of fittings - tight into a corner.

I thought these might be the answer to my problem, but have no experience of the quality or reliability of these reducers. All my compression fitting experience has been on stuff like Swagelok and Whitey fittings on high pressure gas where it's difficult to miss a bad fitting.

 

[leakydave]

One-piece if two pieces less to lose than three-piece.