Abstract: A safety relief valve (10) has a diaphragm actuator (24) including a diaphragm (26) with a dome chamber (34) on one side of the diaphragm (26) and an underdome chamber (36) on an opposed side of the diaphragm (26). A diaphragm operated pilot control valve (38) has a valve body (46) with a pilot sensing port (54), a pilot dome port (64), and a pilot underdome port (60) in fluid communication with a pilot valve chamber (52). A slidable pilot valve member (68) connected to diaphragm (42) is mounted for movement between two pairs of opposed annular seats (80, 84 and 82, 86). Actuation of pilot valve member (68) at a low set pressure permits fluid communication of inlet fluid from pressure vessel (15) to underdome chamber (36) and exhaust of fluid from dome chamber (34) to boost opening of main relief valve member (22).

Abstract: A gas regulator valve (14) for maintaining a preset low gas pressure in a storage tank (10). A fluid balanced piston valve member (32) is seated in a closed position on seat (40). A diaphragm actuator (70) has a diaphragm (76). A linkage including opposed link arms (106, 108) is positioned between the diaphragm (76) and the piston valve member (32) and a roller (104) supported on link arms (106, 108) contacts the valve member (32) for controlling the movement of the valve member (32) between open and closed positions. The inner upper ends of link arms (106, 108) are pivotally mounted on bracket (94) secured to the housing and the lower outer ends of the link arms (106, 108) are pivotally mounted on opposed brackets (88, 90) secured to the diaphragm (76). An axial movement of the diaphragm (76) of about two inches results in an axial movement of roller (104) and piston valve member (32) of about 0.20 inch to provide a ratio of about ten to one.

Abstract: A safety relief valve (10) having a main valve member (22) in a normally closed seated position has a diaphragm actuator (24) with a dome chamber (34) adjacent the outer side of the diaphragm (26). A pilot valve (28) is in fluid communication with the dome chamber (34) through a dome line (35) for controlling the opening and closing of the main valve member (22). An underdome chamber (40) on the inner side of the diaphragm (26) has an underdome line 44 extending to an underdome control valve (42) for controlling fluid communication to underdome chamber (40) from the inlet (18). An inlet line (48) extends from the inlet (18) to the underdome control valve (42). When the set pressure of the pilot valve (28) is reached, inlet fluid pressure on the inner side of the diaphragm (26) increases while dome pressure in the dome chamber (34) decreases.

Abstract: A safety relief valve (12) for a pressure vessel (10) in which the main valve member (28) includes a valve plate or disc (52) and a retainer plate (64) having a flexible membrane or diaphragm (62) stretched therebetween in a taut relation to provide a frusto-conical shape (FIG. 3) for obtaining bubble-tight sealing against valve seat (26). A fluid chamber (116) is provided between valve plate (52) and retainer plate (64) and inlet fluid pressure is communicated through opening (118) of jack screw (106) to the fluid chamber (116) for providing inlet fluid pressure thereto to force valve plate (52) and retainer plate (64) apart for tensioning of flexible membrane (62) into a frusto-conical shape. A jack screw (106) is threaded within a bushing (94) carried by retainer plate (64). Upon rotation of jack screw (106), valve plate (52) and retainer plate (64) are forced away from each other for tensioning flexible membrane (62) into a frusto-conical shape.

Abstract: A vertically oriented float assisted automatic driptrap mechanism having a float valve chamber defined by a body section and base is disclosed. A float is located for vertical liquid level responsive movement within the float valve chamber and reciprocates within a valve stem float guide. A diffuser is provided at the inlet of the chamber to prevent impingement of incoming fluid on the float. The valve stem guide also serves as a filter support for a filter which filters out contaminants that might interfere with the valving action of the driptrap mechanism. A valve seat having a tapered seat surface and a self-positioning valve plug movably supported by the valve stem and having a differently tapered sealing surface establish line contact sealing to ensure effective valve operation under high pressure conditions.

Abstract: A diaphragm controlled spring loaded regulator is disclosed. Such regulator is adapted to regulate the flow of compressed gas applied to a gas blanket on top of liquids in a storage tank and to other low pressure applications. The regulator includes a piston in a valve body with an "O" ring seat contacting an annular seating surface of the valve body. A compression spring is located on one end of the piston and a diaphragm actuator responsive to remote tank pressure is provided on the other end of the piston. At closure, the piston is pressure balanced. One arrangement is provided with a rollout seal in combination with an upper piston part and tapered cylinder walls such that after the piston begins to open, increased opening force is created due to inlet pressure acting on the upper piston part. As the piston begins to close, increased closing force is created due to inlet pressure.