Studor Air Admittance Valves (AAV) in Drainage Systems

Innovation:

Year:

1994

Description:

The concept of sealing the drain of a plumbing fixture with a water trap and venting the plumbing line to maintain that seal has existed for many years. Ordinarily, such a vent system relies on a series of pipes that run from each fixture's trap and merge into a single pipe that extends to a high point outdoors where the end of that pipe can be left open to the air. The water trap seal prevents sewer gas from escaping into habitable spaces and is necessary for safety and health of the buildings occupants. The purpose of the vent is to balance the pressures in the drainage system so that the water in the trap is neither sucked down the drain nor forced out into the fixture.
The Studor Air Admittance Valve is a plastic device designed with a sealing member, or diaphragm, that opens to admit air by lifting upward when a negative pressure occurs as the water falls in the drainage system. Once the air pressure in the system is balanced, it closes by gravity. There are no springs or levers that can fail. The diaphragms are made of synthetic rubber. The Studor Valve has screens to prevent the admittance of vermin such as roaches or mice that can interfere with the operation of the diaphragm. The valve has an insulation cap of foamed plastic to prevent freezing and frost closure when used in a cold environment. The valve also prevents the "chimney effect" in the pipe that develops when a fire occurs, especially in plastic piping systems.

Related Standards:

Contact Person:

John R Nussbaum

Organization:

Plumbing, Heating and Cooling Contractors Association of Southeastern Michigan

Address:

14801 West Eight Mile Road

City:

Detroit

State/Province:

Postal Code:

48235

Country:

USA

Phone No.:

313-345-3535

FAX:

URL:

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This page last updated 05/15/02 by RICarr