dishwasher waste trap

[Fred]

Hi,

In the process of removing the old kitchen units, I have found that the dishwasher waste is plumbed in solvent weld pipe and the installer has created a running trap using some 45 degree joints to make a trap like this: \ _ /

I was just going to run a length of pipe to an off-the-shelf washing machine trap.

Is one approach better than the other? I guess solvent weld cannot fall apart or leak but properly installed, neither should the compression fitting washing machine trap.

If making a running trap, I think he should have used a tee and fitted a plug into the one end, so that any blockage could be cleared. That seems to be the problem with the solvent weld trap: that it was inaccessible under the cupboard, so whatever is used needs to be accessible.

If making your own, are swept 92 degree joints better than 45 degree ones? What is the minimum seal depth?

What does the group think?

TIA

[Tim Watts]

On Friday 17 May 2013 15:29 Fred wrote in uk.d-i-y:

I used 2 tees, and 2 swept bends. In 50mm! But this was to take 2 standpipes into from a washing machine and dishwasher, hence the careful design to ensure no reasonable backpressure could so bad things.

I also put screw caps on the tops of the 2 standpipes so if one is out of use, you can cap it off :)

As to your 45 degree ones - probably fine. These traps almost never block (unlike sinks) as they generally do not get heavy amounts of fat flung down them and they also get a good purge with high flow very hot detergent laden water on a regular basis.