On 25/06/15 21:53, Fredxxx wrote:
These will be next to each other.

There is very little room behind these appliances and was wondering how
practical it is to have a common waste system.

Are there any regulations on the horizontal length of the U trap, such
that I can make a combined trap for both. I would use 40mm pipe,
possibly solvent weld.


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This diagram will only work with fixed width fonts.

I did exactly that.

But I made the trap out of 50mm elbows and tees (2 tees with a cap on
the top of each end to allow for cleaning).

Works rather well.

However, I find that it was a good idea to do this:

A B
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The dip is 2 x 45 degree bends end to end. It is not much but it stops
back pressure from stand pipe A pushing back up B

I also finished A and B with screw caps so if either is not used it can
be blanked off.