MDPE to 3/4 thread (is it 3/4 thread ????)

[frank999]

I have one of these, I also have floplast MDPE to 3/4 adapters:

I can't get any 3/4 (22mm) compression fittings to fit the plastic thread, few turns in they all cross thread and strip the plastic thread in the MDPE fitting ...

Am I missing something ??

 

[denso13]

22mm won't fit you need a 3/4" adapter. 22mm fittings don't have 3/4" threads. https://www.toolstation.com/compression-coupler-male/p57822

 

[frank999]

Ahh, thanks ... been driving me nuts, it appears 22mm compression threads are indeed NOT 3/4" BSP, seems the thread is not to any particular standard, now I think about it - I have a variety of 22mm nuts that have different threads.