Abstract: A pressure relief or back pressure valve has a valve body with a tubular outlet member having an outlet surrounded by an end face and an annular inlet chamber surrounding the outlet member. The annular inlet chamber has an outer periphery defined by a wall member with an end face in a plane spaced away from a plane defined by the end face of the outlet member. A flexible diaphragm has an outer peripheral edge portion clamped between the end face of the wall member and a clamping member, the flexible diaphragm in an undeflected configuration having a central portion spaced from the end surface of the outlet member. A resilient force applying device is operable to apply a predetermined force to the diaphragm to cause the diaphragm to be deflected into engagement with the end face of the outlet member, and a release device is operable to remove the force from the diaphragm to permit the diaphragm to move away from the end face of the outlet member.

Abstract: A pressure relief or back pressure valve has a valve body with a tubular outlet member having an outlet surrounded by an end face and an annular inlet chamber surrounding the outlet member. The annular inlet chamber has an outer periphery defined by a wall member with an end face in a plane spaced away from a plane defined by the end face of the outlet member. A flexible diaphragm has an outer peripheral edge portion clamped between the end face of the wall member and a clamping member, the flexible diaphragm in an undeflected configuration having a central portion spaced from the end surface of the outlet member. A resilient force applying device is operable to apply a predetermined force to the diaphragm to cause the diaphragm to be deflected into engagement with the end face of the outlet member, and a release device is operable to remove the force from the diaphragm to permit the diaphragm to move away from the end face of the outlet member.