Abstract: A pump includes a cylindrical plunger chamber having an inward projecting radial seal. A plunger moves with a reciprocating stroke within the cylindrical plunger chamber, the plunger having a first diameter, and a second diameter less than the first diameter, the radial seal engaging the plunger at the second diameter for an entire length of the stroke of the plunger. A pressure balancing valve is in fluid communication with the pumping chamber and the hydraulic oil chamber. A fluid passage connects to the plunger chamber at a position between the radial seal and the first diameter of the plunger and leads to the pressure balancing valve. A radial clearance is between the cylinder and the second diameter, and a seal between the first portion and the cylinder having a clearance smaller than the radial clearance allows hydraulic fluid to escape past the seal during a plunger stroke.

Abstract: A diaphragm pump and a valve system each include a valve plate having a planar valve engaging surface, a plurality of planar valve seats formed in the valve engaging surface, and a hole extending through each of the valve seats to an opposite face. Valves are disposed in the valve seats. Each of the valves includes a stem having a longitudinal axis extending through an associated one of the holes, and a flap at a first end of the valve extending transversely to the longitudinal axis. The stem and the flap have a non-circular cross-section, and a width of the flap and stem transverse to the longitudinal axis is greater than a depth of the flap and stem transverse to the longitudinal axis along the valve.

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 (18) includes a disk-shaped center planar portion (40) and a first lip (42) and a second lip (44) on the outermost edge of the disk shaped portion (40) and extending transversely to the planar disk portion (40). The first lip (42) is on a first side of the diaphragm (18) and the second lip (44) is on an opposite side of the diaphragm (18). A mounting portion (38) extends outward from the center of the face of the planar portion (40) on the first side of the diaphragm (18). For metering pump applications pumping harsh fluids, the diaphragm (18) is typically made from a fluoropolymer and in particular may be made from polytetrafluoroethylene (PTFE).

Abstract: A diaphragm pump includes a housing having a pumping chamber containing fluid. The pump has a transfer chamber containing hydraulic fluid, and a hydraulic fluid reservoir in fluid communication with the transfer chamber. The pump housing forms a cylinder with a piston defining a piston inner chamber and sliding in the cylinder. A valve leads to the piston inner chamber with a valve spool slidably mounted in the piston inner chamber to cover the valve and uncover the valve. A diaphragm connects to the valve spool by a plunger. An overfill limiter includes a spacer slidably mounted in the piston inner chamber. A first spring is intermediate the valve spool and the spacer and a second spring is intermediate the end of the piston inner chamber and the spacer, the second spring having a second spring constant greater than the spring constant of the first spring.

Abstract: A hydraulically driven pump includes a diaphragm, a piston, a transfer chamber, a fluid reservoir, and a valve spool. The transfer chamber is defined between the diaphragm and piston and is filled with a hydraulic fluid. The fluid reservoir is in fluid communication with the transfer chamber via at least one valve. The valve spool is configured to control fluid flow between the transfer chamber and the fluid reservoir. The valve spool is movable to open and close an opening into the at least one valve only when an overfill condition or an underfill condition exists in the transfer chamber. The valve spool is moveable along an axis that is non-coaxial with an axis of movement of the diaphragm.

Abstract: A hydraulically driven pump includes a first chamber exposed to a process fluid, a second chamber configured to retain a hydraulic fluid, and a multi-layer diaphragm positioned between the first and second chambers. The diaphragm includes a first layer in contact with the process fluid being pumped, a second layer in contact with the hydraulic fluid, and a third layer that includes an elastomeric base material and an elastomeric conductive trace embedded in the elastomeric base material. The third layer is positioned between the first and second layers and being movable relative to the first and second layers. Changes in an electrical resistance of the conductive trace indicate a failure condition in one of the first, second and third layers.

Abstract: A hydraulically driven pump includes a diaphragm, a piston, a transfer chamber, a fluid reservoir, and a spool member. The transfer chamber is defined between the diaphragm and piston and is filled with a hydraulic fluid. The fluid reservoir is in fluid communication with the transfer chamber via at least one valve. The spool member is configured to control fluid flow between the transfer chamber and the fluid reservoir. The spool member is movable to open and close an opening into the at least one valve only when an overfill condition or an underfill condition exists in the transfer chamber.

Abstract: A magnetically driven pump includes a casing, a containment shell fixed to the casing, a shaft fixed at a closed end of the containment shell, an impeller rotatable about the shaft within the casing and containment shell, and a magnetic coupling removably secured to the impeller and rotatable about the shaft. The pump also includes a rear bearing positioned between the propeller and the shaft that is rotatable about the shaft, and a thrust control valve that includes a thrust ring positioned between the containment shell and the rear bearing. An opening of the thrust control valve is defined by a variable spacing between the thrust ring and the rear bearing.

Abstract: A diaphragm pump which overcomes the problem of diaphragm failure due to overfill of the oil transfer chamber. An overfill preventive element in the form of a mechanical stop, a fully closed coil spring, or a valve system, or alternatives are provided.

Abstract: A hydraulically driven pump includes a first chamber exposed to a process fluid, a second chamber configured to retain a hydraulic fluid, and a multi-layer diaphragm positioned between the first and second chambers. The diaphragm includes a first layer in contact with the process fluid being pumped, a second layer in contact with the hydraulic fluid, and a third layer that includes an elastomeric base material and an elastomeric conductive trace embedded in the elastomeric base material. The third layer is positioned between the first and second layers and being movable relative to the first and second layers. Changes in an electrical resistance of the conductive trace indicate a failure condition in one of the first, second and third layers.

Abstract: A hydraulically driven pump includes a first chamber exposed to a process fluid, a second chamber configured to retain a hydraulic fluid, and a multi-layer diaphragm positioned between the first and second chambers. The diaphragm includes a first layer in contact with the process fluid being pumped, a second layer in contact with the hydraulic fluid, and a third layer that includes an elastomeric base material and an elastomeric conductive trace embedded in the elastomeric base material. The third layer is positioned between the first and second layers and being movable relative to the first and second layers. Changes in an electrical resistance of the conductive trace indicate a failure condition in one of the first, second and third layers.

Abstract: A hydraulically driven pump includes a first chamber exposed to a process fluid, a second chamber configured to retain a hydraulic fluid, and a multi-layer diaphragm positioned between the first and second chambers. The diaphragm includes a first layer in contact with the process fluid being pumped, a second layer in contact with the hydraulic fluid, and a third layer that includes an elastomeric base material and an elastomeric conductive trace embedded in the elastomeric base material. The third layer is positioned between the first and second layers and being movable relative to the first and second layers. Changes in an electrical resistance of the conductive trace indicate a failure condition in one of the first, second and third layers.

Abstract: A diaphragm pump which overcomes the problem of diaphragm failure due to overfill of the oil transfer chamber and the inability to self-prime. A notch is provided in the upper portion of the surface of the cylinder so that air can be forced back to the reservoir. In addition, the bias spring connected to the diaphragm and supported by the piston is made stiff with a spring constant that produces a bias pressure that can overcome abnormal suction pressures.

Abstract: A diaphragm pump which overcomes the problem of diaphragm failure due to overfill of the oil transfer chamber. An overfill preventive element in the form of a mechanical stop, a fully closed coil spring, or a valve system, or alternatives are provided.

Abstract: A diaphragm pump which overcomes the problem of diaphragm failure due to overfill of the oil transfer chamber and the inability to self-prime. A notch is provided in the upper portion of the surface of the cylinder so that air can be forced back to the reservoir. In addition, the bias spring connected to the diaphragm and supported by the piston is made stiff with a spring constant that produces a bias pressure that can overcome abnormal suction pressures.

Abstract: The invention provides a system and method for proportion metering multiple fluids together that are output from different pumps. The invention further provides a system and method for batch signal metering that provides feedback on the amount of fluid that has been dispensed. The invention has applications in numerous technologies, including metering together pest control fluids, such as those used for termite control; metering lawn care fluids such as herbicide and fertilizer; blending colors used in dyes, paints and the like; personal care products such as lotions; water treatment; and other technologies in which different fluids are pumped by separate pumps and thereafter mixed together downstream of the pumps prior to being dispensed.

Abstract: A lawn care applicator system which is used on a vehicle having a vehicle electrical power system. The lawn care applicator system is specifically designed to be easy to use by an operator and to minimize electrical current usage, thereby allowing use of the applicator system with standard vehicle electrical power systems. The applicator system includes an applicator module that is removably mountable on the vehicle. The applicator module preferably includes a housing, at least one liquid supply tank disposed in the housing, and a liquid dispensing system disposed in the housing and connected to the liquid supply tank for dispensing liquid from the liquid supply tank and onto a lawn. A control system is electrically connected to the applicator module for providing power to, and controlling the operation of, the applicator module. The control system is adapted to be connected to the vehicle electrical power system to provide electrical power for the applicator system.