Abstract: A diaphragm pump system includes a diaphragm pump and a pressure regulator. The diaphragm pump has a housing having a pumping chamber containing fluid to be pumped, and a transfer chamber adapted to contain hydraulic fluid. A diaphragm is supported by the housing and at least partially defines a pumping chamber side and a transfer chamber side. A driven plunger slides in a reciprocating motion and forcing hydraulic fluid against the diaphragm. A first valve allows hydraulic fluid into the transfer chamber and a second valve allows hydraulic fluid to be removed from the transfer chamber. A hydraulic fluid reservoir is in fluid communication with the transfer chamber. The pressure regulator includes valving that provides a hydraulic fluid pressure above a pumped fluid inlet feed pressure to maintain a proper amount of hydraulic oil in the transfer chamber.

Abstract: A valve includes a valve disc movable along an axial direction and has an arcing outer engagement surface with an axis of curvature transverse to the axial direction. A valve seat defines a central opening aligned with the axial direction. The valve seat has a toroidal radially inner engagement surface around the central opening configured to engage the engagement surface of the valve disc in a closed position. The engagement surface of the valve disc and the engagement surface of the valve seat are configured to form a line of contact between the outer engagement surface and the inner engagement surface. The engagement surfaces of the valve disc and of the valve seat may be a carbide or ceramic material having a hardness of 1000 HV or more.

Abstract: A regulator valve includes a valve body defining a central bore with a longitudinal axis. A rod couples to a diaphragm and slides along the longitudinal axis within the central bore. The rod has a planar end. A spring, such as a helical spring, mounts in the central bore and engaging the rod. One or more parallel passages are formed in the valve body extend parallel to the bore. One or more slots are formed in the valve body, each of the one or more slots connecting one of the one or more parallel passages to the central bore. The regulator valve may be used in a pumping system as a pressure regulator.

Abstract: A diaphragm pump system includes a diaphragm pump and a pressure regulator. The diaphragm pump has a housing having a pumping chamber containing fluid to be pumped, and a transfer chamber adapted to contain hydraulic fluid. A diaphragm is supported by the housing and at least partially defines a pumping chamber side and a transfer chamber side. A driven plunger slides in a reciprocating motion and forcing hydraulic fluid against the diaphragm. A first valve allows hydraulic fluid into the transfer chamber and a second valve allows hydraulic fluid to be removed from the transfer chamber. A hydraulic fluid reservoir is in fluid communication with the transfer chamber. The pressure regulator includes valving that provides a hydraulic fluid pressure above a pumped fluid inlet feed pressure to maintain a proper amount of hydraulic oil in the transfer chamber.

Abstract: A diaphragm pump includes a transfer chamber containing hydraulic fluid and a pumping chamber for fluid to be pumped. A connecting assembly includes a plunger extending to the transfer chamber. A diaphragm connects to the connecting assembly and separates the transfer chamber and the pumping chamber. A pressure protection device mounts to the connecting assembly and is configured to seal against the transfer chamber when pressure differential, including reverse pressure differential, across the diaphragm exceeds a predetermined value. The pressure protection device is intermediate the plunger and the diaphragm and supports the diaphragm when there is excess pressure differential across the diaphragm.

Abstract: A diaphragm pump includes a transfer chamber containing hydraulic fluid and a pumping chamber for fluid to be pumped. A connecting assembly includes a plunger extending to the transfer chamber. A diaphragm connects to the connecting assembly and separates the transfer chamber and the pumping chamber. A pressure protection device mounts to the connecting assembly and is configured to seal against the transfer chamber when pressure differential, including reverse pressure differential, across the diaphragm exceeds a predetermined value. The pressure protection device is intermediate the plunger and the diaphragm and supports the diaphragm when there is excess pressure differential across the diaphragm.

Abstract: A fluid device includes a housing and a rotor assembly disposed in the housing. The rotor assembly includes a core and a coating. The core has a first surface, an oppositely disposed second surface and an outer peripheral surface that extends between the first and second surfaces. The core defines a bore that extends through the first and second surfaces. The coating coats at least a portion of the core. The coating is a water-swellable plastic material.

Abstract: A rotary fluid device having a housing that defines a pumping chamber, a shaft disposed in the housing, and a rotor disposed in the pumping chamber and engaged with the shaft. The rotor includes a body which defines a bore that includes an oblique tapered surface. A pivot line is disposed along the tapered surface. The pivot line is a circumferential line at which the rotor pivots. A method for manufacturing a rotor includes turning an outer peripheral surface of the rotor. A bore is formed in the rotor. The bore includes an oblique tapered surface that has a pivot line disposed along the tapered surface, wherein the pivot line is a circumferential line at which the rotor pivots.

Abstract: A fluid device includes a housing and a rotor assembly disposed in the housing. The rotor assembly includes a core and a coating. The core has a first surface, an oppositely disposed second surface and an outer peripheral surface that extends between the first and second surfaces. The core defines a bore that extends through the first and second surfaces. The coating coats at least a portion of the core. The coating is a water-swellable plastic material.

Abstract: A rotary fluid device having a housing that defines a pumping chamber, a shaft disposed in the housing, and a rotor disposed in the pumping chamber and engaged with the shaft. The rotor includes a body which defines a bore that includes an oblique tapered surface. A pivot line is disposed along the tapered surface. The pivot line is a circumferential line at which the rotor pivots. A method for manufacturing a rotor includes turning an outer peripheral surface of the rotor. A bore is formed in the rotor. The bore includes an oblique tapered surface that has a pivot line disposed along the tapered surface, wherein the pivot line is a circumferential line at which the rotor pivots.