Bath Trap question

[Sonic70]

I was thinking of fitting a low extended mcalpine trap sm10e which has a 60mm seal to my bath, my question is are these traps only meant to be used if discharging into a hopper only.

Thanks all

 

[Hugh Jaleak]

Minimum 50mm depth of seal, can reduce to 38mm if discharging to a gulley or hopper.

 

[Sonic70]

Ah I thought I read somewhere that 75mm was the min depth for bath seal if its not going to hopper or gulley. Thanks for that info.

 

[Hugh Jaleak]

I've got 75mm in my head, but double checking the regs and they state 50mm. Odd.

 

[Elkato531]

A bath gets away with a 50mm trap because as a large flat bottomed vessel, the last bit of water to empty out of it flows quite slowly and there is less chance of trap loss due to momentum or self siphonage. This can be reduced to 38mm if not connected to a stack as there is less chance of induced siphonage. Having said that, I bet if you looked at 100 baths discharging into a stack, 75% of them would have a shallow trap fitted.

 

[Sonic70]

Thanks all, I will fit the 60mm trap.