Do I need a non-return valve here?

[barki]

Hi

Just plumbing in a new bathroom.


It makes logical sense in the room to plumb the sink waste into the pan connector so it flows into the soil pipe. I've bought a right angle pan connector that has a 32mm socket on it to take the sink waste.

Should I be putting a non return valve (like this) between the sink trap and the pan connector? These only seem to exist in 40mm fitting, so I guess I'd use 2x solvent weld 32mm/40mmr reducers to get this in.

The reason I ask is based on concern that back pressure from flushing the toilet will empty the sink trap and allow smell from the soil pipe into the room.

Any thoughts really appreciated

Cheers,

Tom

 

[picasso]

You dont need a non return valve, install a trap with an aav and you wont have any problems with the trap being emptied.

 

[barki]

Cheers for the response, whats an AAV?

 

[barki]

Ah, air admittance valve, gotya, cheers mate, tom

 

[Madrab]

Just ask for a 32mm Anti Vac trap for the basin.