Kitchen sink waste spout for dishwashers

[WWilts]

New build in progress.

 

Kitchen sink waste kit has single spout to take 1 dishwasher (pic)

How to connect 2 dishwashers? (are spout splitters available? something else to make this work?)

 

PS Sauber double sink, waste kit appears to be European measurements rather than standard UK (pics)
 

Edited November 23, 2022 by WWilts
pics added

[ProDave]

Add one of these to your existing trap

 

https://www.screwfix.com/p/mcalpine-v33s-compression-domestic-appliance-tee-piece-connector-white-40mm/4167p

 

 

 

[MJNewton]

4 hours ago, ProDave said:

Add one of these to your existing trap

 

https://www.screwfix.com/p/mcalpine-v33s-compression-domestic-appliance-tee-piece-connector-white-40mm/4167p

 

 

 

 

I think that'd lower the trap outlet too much.

 

Personally I'd remove the current setup and replace it with a McAlpine SSK2 double bowl space save kit:

 

 

It gives two appliance inlets and a third universal inlet should it be required for something else. It also pushes all the gubbins out of the way (often to the back wall but obviously you've got pipework there already but it could sit in front of that) thus freeing up loads of cupboard space. 

 

[Nickfromwales]

Combination ‘appliance’ traps are horrible gurgley noisy things. 
Can you get a washing machine up stand  in there to take both discharges? 
 

Link

 

You simply fit a compression T into this and create 2x up stands for both discharge hoses to ‘poke’ into. You can go ‘posh’ and fit one of these; Link on top of that single up stand to be completely silent ( very close to ) during discharge. 

A client of mine has recently employed a 2nd fix plumber, and he’s connected their washing machine to a combination waste and it’s noisy as feck. 👎. A good reminder to never do that. 

[WWilts]

On 23/11/2022 at 20:15, Nickfromwales said:

You can go ‘posh’ and fit one of these; Link on top of that single up stand to be completely silent ( very close to ) during discharge. 

Would this work as well? (T cut into the 40mm waste)

 

Because the waste goes into a soil pipe with foul WC waste, perhaps with an air admittance valve added after the dishwasher waste? So that the stench is less likely to enter the 2 dishwashers that drain into the double nozzle?
 

Edited November 25, 2022 by WWilts

[MJNewton]

The issue with that is that it is downstream of the trap (and its water seal) and thus exposed to the sewer. Whilst the connected appliance almost certainly has a sealing sump thus blocking smells from coming through I wouldn't want to rely on it.

 

Edit: It could go on the top pipe though, although note that it is likely a non-standard diameter (but decent compression fittings usually have a decent amount of tolerance).

Edited November 25, 2022 by MJNewton

[WWilts]

2 minutes ago, MJNewton said:

downstream of the trap (and its water seal) and thus exposed to the sewer.

True. Perhaps a bottle trap with AAV on the waste, after the double nozzle T?

[MJNewton]

You may not have seen my edit (apologies) but I think your idea (teeing in) would be fine on the top pipe.

[Nickfromwales]

If you like gurgles, then agreed with top pipe T. 

[MJNewton]

I was meaning to ask about the gurgling concern - can you elaborate? I've had lots of these types of connections and never had any such issues. Can't be just luck or can it? 

[ProDave]

We have dishwasher into the kitchen waste and washing machine into the utility waste.

 

It is true, that when one empties, you hear the water running out of it and down the sink trap.  I assume this is what @Nickfromwales refers to as "gurgling"

 

When the appliance is not in use it makes no other noise.

 

Personal preference if that noise bothers you, but if that noise bothers you then chances are just the noise of the appliance also bothers you.  We have a dishwasher in the kitchen as that's the obvious place but I would regard it as a VERY backward step to have a washing machine there. That is what a utility room is for, tucked away so the noises of the stuff in there don't bother you.