Screwfix bar mixer problem

[Groovejet]

Has anyone came across this problem.
We use the fast fix shower kits, bring two stalks of pipe out wall then the wall plate fittings go on and easier job than the old offset 1/2" x 3/4" fittings.
Anyway the 3/4" connection that connects shower bar protrudes on the inner part, so that the fitting doesn't bite up to the rubber washer, and in turn , just really slack.
I unscrewed them but it's in one piece, with the non return valves in them also .
Thought about cutting protrusion off but then the spring washer holding the non return valves will fall to pieces.

Is there anywhere to get replacement fittings?
There also a left hand thread?

 

[terryplumb]

Is the copper supply pipe too long ,I.e is the nr valve hitting the end of the copper ? I have never come across a bar mixer with a left hand 3/4 thread.

 

[DH6]

I find this with triton bar mixers, get the swirl shower fixing kits from screwfix, they fit