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 differential pressure (static condition) and under positive pressure. These devices prevent sewer gases from entering the building. The device consists of a hooded or shielded body which contains a movable sealing assembly that 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 be rated to pass the air rate indicated in Table 1 without exceeding a pressure drop greater than 1.0 inch (25.4 mm) water column.