On 07/05/2015 12:40, Jim x321x wrote:
Does anyon know if any building reg specifying that the female end of a
coupler must point backwards (uphill, towards the flow source), and the
male end of the coupler must point forward (downhill, in the direction of
the flow)? I have a situation where it would be much more convenient to
have one coupling the other way round.

The statutory requirements are set out in British Standards:

BS EN 752: 2008 Drain and sewer systems outside buildings.
BS EN 1610: 1998 Construction and testing of drains and Sewers

There is also another relevant standard:

BS 5955: Part 6 : 1980 Installation of PVCu pipework for gravity drains
and sewers

You should be able to view these at your local public library, although
branch libraries may need to borrow them from a central reference library.

--
Colin Bignell