Gully trap replaces vent stacks??

[jor1492]

Hi all,

My question is if I have a Gully trap in my Drain Waste and Vent plumbing system, I do not need to add vent stacks or another venting system in my Drain Waste and Vent plumbing system?
This is because I am working in a project of a house residential village but using New Zealand Specs, and in my country the normal is The International Plumbing code.
I want to know also if this thing of Gully trap is something only of the new Zealand plumbing code or it is also use in the international plumbing code.

Thanks in advance

 

[PEDARRIN2]

It appears to be a "master trap" which used to be used to prevent vermin and exterior sewer gases from entering the building. It is not allowed per the IPC, but check your local AHJ, because they tend to edit the IPC for their local codes.

 

[dbill74]

Never heard of a Gully trap.

All traps are intended to provide a seal to prevent sewer gases and vermin from entering the occupied spaces of a building as Pedarrin said.

Vent systems are required to maintain a pressure balance between the two sides of a trap and facilitate smooth flow through the trap. Without a vent system, pressure differentials on the sewer side can move water in a trap to break the trap's seal, negating the purpose of the trap. Improperly sized or located vents can cause siphonage of the trap or a blow out.