TUUBER PVC Pipe Threads 2 in. Air Admittance Valve

The purpose of an air admittance valve is to provide a method of allowing air to enter a plumbing system as an alternative to a vent extended outside a building to outside air and to prevent plumbing system sewer gases from entering inside a building and to protect against siphonage of a plumbing fixture trap. The DUAL-SEAL 20 air admittance valve is the only patented dual sealing air admittance valve that prevents sewer gases and odors from entering inside a building and protects against siphonage of a plumbing fixture trap. DUAL-SEAL 20 air admittance valve opens to satisfy negative pressures that can develop in the plumbing drainage system when the fixture begins to drain allowing air from inside the building where installed to enter the plumbing drainage system. DUAL-SEAL 20 air admittance valve closes by gravity at zero (0) differential pressure preventing plumbing system sewer gases from entering inside a building. DUAL-SEAL 20 air admittance valve seals are test ready for use in existing and new plu...