Air Admittance valve

[mitrepooc]

Does an air amittance valve have to be fitted vertically & above the discharge stack?
The reason being is i'm installing the pipework for a proposed downstairs toilet unfortunately i cant fit a conventional soil stack arrangement (vertically)
I'm proposing to come from the toilet into a 90deg pan connector then into an equal tee one end connecting to main pipe which is connected to a mini access chamber, the other end of the tee is connected to a short horizontal pipe then a 90deg bend, up the wall for a approx 1m then capped with air admittance valve, in your opinion(s) will this work?
Any advice greatly app'd
Tim.

 

[kevplumb]

approx 600 above the basin rim

 

[mitrepooc]

Hi Kev,
Thanks for the reply & image.
The soil stack arrangement shown is not the arrangement i can do.
My connection to the main discharge pipe all happens under the suspended floor, the picture shows a conventional soil stack arrangement with the pan connector running horizontally above floor level.
I don't think i have explained what I'm proposing very well but please bear with me
I want to connect the 90deg pan connector to go down (underfloor) into an equal tee one end connected to the main pipe running to a new mini access chamber the other connected to a short piece of pipe (still underfloor) with a 90deg elbow pointing up & another piece of pipe connecting to the elbow (above floor level) with the air admittance valve.
Space is at a premium the room only being 1.2m by 1m.
The (compact) toilet i have bought can only go in one position hence the unusual arrangement i have proposed.
If i still make no sense I'll try & take some pic's & post a link to them here.
Many thanks again for your help.
Tim.

 

[kevplumb]

sounds ok as long as the pipe is above flood level

 

[mitrepooc]

Excellent, thanks for the help Kev
Tim.