Re: In-line vent alt.
Posted by Layman on December 04, 2003 at 14:50:58:
In response to Re: In-line vent alt.
: : Nice picture. Where's the AAV? I hope it is not the time coming horizontally out of the vent stack.

: Reply:
: I figured you would know that I was being sacastic hj.
: The picture was meant to show the installer the correct way to install a WM drain, at least what I consider correct. Most people are eager to install an AAV because running a vent line is "impossible".
: ...The fitting on the vent is a clean-out fitting.
: e-plumber

AAVs are routinely used to vent washing machines and sinks with garbage disposals. Turbulent pressure conditions in the waste system do not cause the valve to malfunction. Even if there is a blockage in the line, water and waste will not come in contact with the valve since an air chamber is formed between the blockage, water trap and AAV. Applying the principle of Boyle's law the air could possibly compress, but it would not disappear, allowing sewage to foul the valve.
If bugs or foreign matter lodge between the sealing membrane and valve seat, sewer gas could escape. Some manufacturers, such as Studor, have specially designed screening inside and outside of the valve to reduce the risk of this happening. Studor's specially designed packaging provides additional protection from foreign objects and debris when installed over the valve. I would like to ask Mr. Saltzberg to explain what happens when an open vent pipe becomes closed due to frost, is blocked by falling leaves, debris or nesting birds and negative pressure conditions are created in vent pipes due to wind shear? Without trying to put words in his mouth, the answer would probably be that the water trap will be siphoned and sewer gases will escape through the fixture drain.
Normal operating pressures in DWV systems are +/- 1 inch water column. All codes require that there be at least one open vent pipe installed on each building drainage system. This provides instant relief of any positive pressure condition before a blowout of the 2-inch water trap seal will occur.
Conclusion Many well-known and reputable consulting mechanical engineers, who are not known to gamble with their reputations, have been specifying AAVs in projects for more than 10 years in the USA and for more than 26 years in Europe. The 1996 Olympic Stadium in Atlanta is just one example. There are approximately 2,000 Studor valves installed in that arena. Also, the engineering firm that has designed the new Detroit Lions football stadium has specified Studor AAVs. There are in excess of 4 million valves installed in the USA, and they are operating successfully. Cost savings are only one of the many benefits AAVs provide compared to open pipe venting, and it is far in excess of only a couple of dollars when you consider the high cost of today's labor coupled with the serious shortage of skilled labor causing longer completion times.

Edward Saltzberg, president of Edward Saltzberg and Associates, is a forensic mechanical engineer. For more information, contractors can visit or call (818) 994-2613.
Jack Beuschel is the president of Florida-based Studor, Inc. He can be reached at 800-447-4721.

: : : : Would the in-line vent(tudor) be placed after the standpipe and P-Trap. A drawing would help.

: : : Reply:
: : : This photo should help you do the install.
: : : Good Luck. e-plumber

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