Anti-syphon trap, but still gurgling

[Nwest]

Hi,

I replaced our trap with an anti-syphon one (and also changed the angle of the washing machine waste). But when the washing machine starts, it still gurgles. Why does that still happen, and more importantly, what else do I need to do?

Please see 2 images before/after:

Thanks in advance!

 

[blup]

Faulty AAV, or maybe the combined flow from WM and sink waste overcomes the anti siphon trap

Blup

 

[Madrab]

The appliance spigots in sink trap will always create water noise as the appliance empties. The water empties into the trap above the bend so all you are hearing is the turbulent water being pumped into the waste, unfortunately you can't get rid of that.

It's not the same 'gurgling' that needs an anti vac trap to correct it, as in, say when the water plug in the pipe when the sink drains or another draining waste run attached to the same outflow pipe then pulls on the trap seal.

 

[Nwest]

Thanks for the comments. Would this have anything to do with washinig machine waste and external waste being almost level? I would have thought that the black waste pipe (RHS) would need to be a bit lower than the left handside. No sure if this is important or not, but if I was setting this up I would have made the black pipe anoter 2cm or so shorter. Am I talking nonsense here?

 

[Hugh Jaleak]

Unavoidable to get some gurgling with any appliance discharge setup. My Dishwasher is connected in a similar fashion the waste pipe drops down immediately after the trap, and it still gurgles somewhat when machine is pumping out. Best advice I think is to learn to live with it.

 

[Madrab]

if I was setting this up I would have made the black pipe anoter 2cm or so shorter. Am I talking nonsense here?

Wouldn't matter, the traps water seal would always be level with the bottom of the outflow of the trap regardless of whether the black pipe was lower than the appliance spigot or not. So the outflow from the appliance drain pipe/spigot would always cause water turbulence, which is then amplified by empty the sink itself.

As suggested, it is something that cannot be eliminated with that setup. Only way to stop draining noise would be to have a stand pipe arrangement behind the appliance and do away with using the sink trap spigot.