Incombatability of Hep20 versus Polyplumb

[Axel]

I understand that one is not meant to use Polypipe with Hep20 fittings or Hep20 pipe with Polyplumb fittings.

Is this due to physical differences of the pipes / fittings or is it just because of legal reasons - ie which manufacturer would be held responsible in the event of failure of a pipe to fitting seal / mechanical failure?

 

[ChrisR]

The outside diameters are the same but different pipes, usually because of materials, can be different thicknesses so need their own inserts.
The fitings work with any plastic, or copper.

 

[Axel]

So what you are saying, is that if the inserts appropriate for the particular brand of PIPE are used, then you can stick polypipe into a hep fitting or visa versa?