Abstract: A pressure relief valve (10) includes a housing (20) defining an air flow passage (34). A flap (90) overlies the air flow passage (34). At least a portion (92, 94) of the flap (90) is movable, in response to an air pressure differential acting on opposite portions of the flap, between an open condition venting air from one side (18) of the valve (10) to a closed condition blocking flow of air from a second side (19) of the valve. The flap (90) has a plurality of mounting openings (104, 106). The housing (20) has a plurality of generally T-shaped mounting posts (70, 72) projecting from the housing. A snap connection is provided between the flap (90) and the mounting posts (70, 72) to secure the flap to the housing (20) with the mounting posts extending through the openings (104, 106). The mounting posts (70, 72) are the only structure holding the flap (90) on the housing (20).