Abstract: A check valve having improved sealing qualities and provided in the form of a replaceable assembly of a valve member and valve seat to avoid the need to replace the valve housing. The sealing surfaces are defined by obliquely directed, outwardly tapering sealing members which are capable of deflection to provide increased sealing area as the pressure on the downstream side of the assembly is increased. The valve assembly includes an annular base having an inwardly directed, tapered valve seat and an annular sleeve secured thereto in coaxial relationship. A spider member is secured to the other end of the sleeve and includes inwardly directed radial means terminating in a hub having a cylindrical bore to support the stem of the valve member. A spring is provided to bias the valve member against the valve seat.

Abstract: A self-priming system for liquid pumps wherein a priming valve is provided to convey a quantity of priming liquid to the pump upon loss of pump suction. A pilot valve is provided to regulate the pressure against a piston which serves to maintain the priming valve closed. The pilot valve controls the liquid pressure exerted against the piston and thereby regulate the pressure level at which the priming valve will open. The pilot valve can be electrically actuated by means of a flow sensor including a diaphragm operated switch responsive to liquid flow.

Abstract: A self-priming pump system including a priming valve for automatically providing priming liquid to a pump which has lost suction. The priming liquid is contained within the pump discharge column between a pair of spaced check valves. The priming valve is in communication with the priming liquid column and is activated by the static pressure head difference between the discharge column and the pump outlet to cause the valve to open upon loss of pump suction, which is reflected in a drop of static pressure head at the pump outlet. The priming valve includes a valve member connected to a piston which is received in a cylinder in communication with the discharge column. A bleed valve and bleed conduit extend from the cylinder to control the pressure level at which the valve will be actuated.

Abstract: A self-priming pump system incorporating a priming valve to release a quantity of priming liquid upon loss of pump suction. The valve includes a piston connected to a valve member, the piston having an area greater than that of the valve member. Discharge line static pressure act upon the valve member and the piston and the difference in area results in a net force tending to open the valve. The valve is maintained closed by the pump discharge dynamic pressure acting through a conduit and upon the opposite face of the piston. The valve does not include any springs or other mechanical biasing means.

Abstract: A self-priming system for liquid pumps wherein a priming valve is provided to convey a quantity of priming liquid to the pump upon loss of pump suction. A pilot valve is provided to regulate the pressure against a piston which serves to maintain the priming valve closed. The pilot valve includes a bleed valve to vary the liquid pressure exerted against the piston and thereby regulate the pressure level at which the priming valve will open.

Abstract: A fluid connection incorporating a metallic seal defined by a pair of cooperating, obliquely oriented sealing lips. The lips taper in thickness and are each carried by one of the connection elements to permit contact therebetween at their respective tips. A passageway from the main fluid conduit is provided to permit the fluid pressure to act against the sealing lips to urge them into tighter contact and thereby provide increased sealing force as the fluid pressure increases.