Resealing Bottle Trap Vs Bottle Trap

[self builder 123]

Hi

I understand that a resealing bottle trap is designed so that the water in the trap can not be "pulled" due to syphonic action.

What actually makes a bottle trap resealing ?

How does the design differ to a standard bottle trap ?

Cheers

 

[kevplumb]

its got an air admittance valve on the outlet

 

[self builder 123]

Hi Kevplumb

MacAlpine make a Silentrap which has an air admittance valve on the outlet, however they also make a resealing trap.

How does the resealing trap work ?

 

[TicklyT]

It looks to me as if they have made the 'bottle' section larger so a partial vacuum can't pull enough water out of the trap to break the seal.