I know this has been answered before but I plumb forgot

[WaterTight]

This product must be not be fit for sale, strictly speaking then...?

PB / PEX Universal Pipe Insert 15mm

 

[WaterTight]

Look at me, 5am on a bank holiday Sunday posting about pipe inserts. Anyone got a spare life? I'm seem to have misplaced mine.

 

[ShaunCorbs]

Depending on the internal wall it could be too tight or too loose

 

[Welder]

All plastic pipe except MLCP (so far as I recall) is gas permeable i.e. lets air through - even barrier pipe. The barrier pipe simply lets less through. The BS (cant recall it) simply states it can let through no more a certain amount.

This is one reason why fitting something like a Spirovent will mean the need to permanently keep an eye on, and top up, system pressures when you have say UF htg installed. For some reason, here in the UK we accept leaking pipes but in places like Hong Kong they don't...

 

[Ric2013]

This product must be not be fit for sale, strictly speaking then...?

PB / PEX Universal Pipe Insert 15mm

I think it's 'universal' in that it fits BOTH kinds of pipe sold on that page of the TS catalogue, not that it fits all 15mm pipe by all manufacturers. Bit misleading...