Abstract: A pressure relief valve is provided including a flapper pivotally mounted to a housing. The flapper is movable between a first position and a second position. A protrusion extends from a first surface of the flapper. A biasing mechanism is positioned near a first end of the flapper. The biasing mechanism is configured to apply a biasing force to the first surface of the flapper. A non-rotatable pin is arranged generally parallel to the first end of the flapper. A drag link is configured to pivot about the non-rotatable pin. The drag link includes a retaining feature and is substantially aligned with the protrusion on the flapper. When the flapper rotates to the second position, the retaining feature is configured to engage the protrusion to retain the flapper in the second position.

Abstract: A pressure relief valve is provided including a flapper pivotally mounted to a housing. The flapper is movable between a first position and a second position. A protrusion extends from a first surface of the flapper. A biasing mechanism is positioned near a first end of the flapper. The biasing mechanism is configured to apply a biasing force to the first surface of the flapper. A non-rotatable pin is arranged generally parallel to the first end of the flapper. A drag link is configured to pivot about the non-rotatable pin. The drag link includes a retaining feature and is substantially aligned with the protrusion on the flapper. When the flapper rotates to the second position, the retaining feature is configured to engage the protrusion to retain the flapper in the second position.

Abstract: A low pitch alarm assembly 70 comprises a capped sleeve 72 disposed about the distal end 55 of the rotating and translating fluid delivery tube 50 so as to define a chamber 75 receiving the end 55 of the fluid delivery tube for axial translation therein, a fluid supply conduit 80, a pressure drop orifice 82 disposed in the fluid supply conduit 80, and a pressure switch 90 opening to the supply conduit downstream of the pressure drop orifice. The sleeve 72 has relatively large flow area outlet holes 74 opening through the capped end 76 of the sleeve 72 to a low pressure and a relatively small flow area inlet opening 73 through the sleeve side wall 78 connected to the fluid supply conduit 80. The pressure switch 90 generates an alarm signal whenever the end 55 of the fluid delivery tube 50 passes out of registration with inlet opening 73.