# PAPA valves



## Rando (Dec 31, 2012)

Anybody else use them yet? They are part of the Studor AAV systems for multi story. You install them at the bottom of the waste stack vent. Basically, the idea is to prevent the water slug from sucking out the traps when it hits the bottom of the stack. 
Kind of an "air cushion". 
Don't know if I'm ever going to get used to this IPC BS.


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## Protech (Sep 22, 2008)

What's the deal with that hanger holding the pex up to the slab? Never seen one of those.


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## Protech (Sep 22, 2008)

Rando said:


> Anybody else use them yet? They are part of the Studor AAV systems for multi story. You install them at the bottom of the waste stack vent. Basically, the idea is to prevent the water slug from sucking out the traps when it hits the bottom of the stack.
> Kind of an "air cushion".
> Don't know if I'm ever going to get used to this IPC BS.


I don't get it. How does it work?


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## Rando (Dec 31, 2012)

Protech said:


> I don't get it. How does it work?


Thats just a piece of uni-strut bolted to the ceiling with PEX clamps holding them. 
The PAPA valve is supossed to help protect the trap seals because the whole building is vented with AAV's except for a few VTR's.
Here's a link to a dumb animation i found. it's not very good but maybe it will help.

http://www.studor.net/movie/papaSL1.mpg


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## Protech (Sep 22, 2008)

I dont get it. the positive pressure has to go somewhere.


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## SewerRatz (Apr 25, 2009)

It's their answer for the postive pressure caused by improper venting (aav). Since a aav works on negative pressure and prevents positive pressure from coming out. As a slug of water travels down the stack its pushing creating positive pressure below it and can blow out sink traps that are vented with an aav.

Aavs should be banned period...well in Illinois they are.


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## UN1TED-WE-PLUMB (Oct 3, 2012)

^^^ You are correct. Should be banned. A venting system has to "breathe". Both inhale and exhale and the auto vents only allow it inhale.


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## user2090 (Sep 26, 2009)

UN1TED-WE-PLUMB said:


> ^^^ You are correct. Should be banned. A venting system has to "breathe". Both inhale and exhale and the auto vents only allow it inhale.



If done right a system with AAV does breathe. Is traditional venting better or the best, yes. Does an AAV system not work, no. So long as they are properly installed according to code, which requires other venting then what is the problem? 

You going to go to an old home and tell the customer that you need to demo a majority of the house so that you can put a vent to each fixture? 

If we are going to get picky over venting then we should also want wet venting banned as there is still a better way.


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## UN1TED-WE-PLUMB (Oct 3, 2012)

I guess they do have their place. My problem around here I see them used improperly a lot.


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## user2090 (Sep 26, 2009)

UN1TED-WE-PLUMB said:


> I guess they do have their place. My problem around here I see them used improperly a lot.



Now there is the real problem. Improperly installed plumbing systems are all too common around here, and as it sounds around the world. 

I've found that retrofitting a AAV in an old house with little to no venting improves the situation, but by no means is it a permanent fix. It would be preferable to put in a proper vent, but telling John Q. Customer that they should spend a thousand or two upgrading their vent system gets you funny looks.


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## CT18 (Sep 18, 2012)

We used the PAPA on MGM hotel and casino in Detroit back in 2005. It was used in conjunction with a sovent system. That was my first CAD job after 20 years in the field, so i was not involved heavily on the system design part of the job. I was just given engineered drawings and told to make it fit in the building with the other trades.


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## plumbing ninja (Jan 15, 2012)

I'm an advocate of Air valves. Biggest problem I see is incorrect sizing, selection and installation (hmmm could say that for most plumbing problems)! It is a preventative measure rather than a corrective one! I've used them more on municipal pipelines & pumping stations and aware of the damage air or vacuum can do! On alot of high rises here we get idiots pulling them out because they don't see it doing anything??


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## dclarke (Dec 22, 2012)

Indie said:


> telling John Q. Customer that they should spend a thousand or two upgrading their vent system gets you funny looks.


I just experienced this a few days ago. a toilet wasnt flushing proper and the tub made the toilet bubble. found no vents in the house. customer didnt want to add a vent because it has been working forever without it.


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