I'm confused - 82mm or 75mm?

[mlgibbons]

Hi
I'm sure this is simple but I can't quite figure it out. I have a stack that I need to vent using a AAV (McAlpine VP50P) which supports 110mm or 75mm pipes. I currently have the AAV inserted into the 110mm pipe and want to move it to another location using a smaller pipe but am confused about the pipe size that I need. Is it 75mm or 82mm? For 75mm pipe I apparently insert into the pipe into the AAV rather than the other way around for 110mm. I've researched it and my understanding is that 82mm pipe is 75mm internal diameter but in that case wouldn't the AAV says that it supports 82mm pipe? More than a little confused!

Thanks
Mark

 

[SafeGasInstall]

I think you have to keep it 4"

 

[Ermintrude]

U can vet to atmosphere using a 75mm but not sure of Aav. Depends on bends and length of extended run as pressure drop would stop Aav working. Sounds stupid but it does!

 

[mlgibbons]

Hi
I'm fine with the AVV and 75mm I just need to know if I need to buy a 75mm pipe or a 82mm one?

Thanks
Mark

U can vet to atmosphere using a 75mm but not sure of Aav. Depends on bends and length of extended run as pressure drop would stop Aav working. Sounds stupid but it does!

 

[mlgibbons]

I just pulled the thing off and measured it: 82mm inside diameter; why on earth they give outside for one and inside for the other is beyond me. Question answered anyway.

Hi
I'm fine with the AVV and 75mm I just need to know if I need to buy a 75mm pipe or a 82mm one?

Thanks
Mark