scope:

Description

These devices consist of a one-way valve designed to allow air to enter the plumbing drainage system when a pressure less than atmospheric develops. The device closes and seals by gravity under zero (0) differential pressure (static condition) and under positive pressure. These devices prevent sewer gases from entering a building. The device consists of a hooded or shielded body which contains a normally closed movable sealing assembly which seats and seals air flow when closed and allows air to enter when open.

Temperature Range

These devices shall function at temperatures from -40.0 °F to 150.0 °F (-40.0 °C to 65.6 °C).

Rating

These devices shall, at a minimum, pass the air flow rate according to Table 1 at -1.0 inch (-25.4 mm) water column.

Note: This corresponds to half the size of a 2-inch (50.8mm) trap diameter for when a trap potentially evaporates.

Pressure Range

Devices are designed to operate within a range of -1.0 inch (-25.4mm) to 1.57 inch (40 mm) of water column.