A plunger pump, including: a tubular cylinder that has an internal space communicating with inlet and outlet flow paths; and a piston that is movable along an axis of the cylinder, wherein a head of the piston includes, on an outer peripheral surface thereof, a sealing portion that is slidable against an inner peripheral surface of the cylinder, which includes a body tubular portion wherein the head is arranged during normal use, and a cleaning tubular portion wherein the head is arranged during cleaning, an inner peripheral surface of the cleaning tubular portion has an inner diameter equal to that of an inner peripheral surface of the body tubular portion, the cleaning tubular portion includes, on the inner peripheral surface thereof, at least one cleaning liquid circulation groove that is configured by a through hole or recess, and the cleaning liquid circulation groove extends obliquely with respect to the axis.

A manually operated pump exhibiting numerous improvement over existing such pumps is described. The pump can include a cylinder that is removeably mounted to a molded valve box of unitary construction. The valve box can feature a valve plate covering a valve chamber and housing an inlet valve and an outlet valve. In some instances, the pump includes a molded piston of unitary construction to which a pair of opposing piston cups is mounted. In some cases, the pump includes a filler cap forming an inlet adapted to deliver a priming fluid into the cylinder. In some cases, the pump includes a stopper cap adapted to prevent a pump shaft from being fully pulled out of the cylinder.

A multiflow pump for fluids, having an electromagnetic translator drive, a displacement piston unit, a pump head, and at least one outlet valve device. The displacement piston contains a bearing journal with a spring receptacle, a carrier plate, and a plurality of pump pistons, wherein the displacement piston unit is configured in one piece.

In a piston including a plurality of piston rings, a state where a difference in differential pressure between the piston rings is eased is maintained even after passage of time, and the life of the piston rings is extended.

A piston includes a piston body in which a plurality of ring grooves is formed, and a plurality of piston rings respectively arranged in the ring grooves. In the piston, a leakage groove is formed on a low-pressure side surface of the ring groove, and in a state where the piston ring is abutted with the low-pressure side surface while being abutted with a cylinder, the leakage groove ensures communication between a high-pressure side space and a low-pressure side space with respect to the piston ring.

The carbon free compressor pump system is a device that utilizes several pistons in a hydraulic or power press manner to compress gas or pump fluids. The device utilizes mechanical advantage of a pulley on the upstroke and uses a clutch device to utilize the gravitational force on the downstroke. In order to accomplish this the device includes a base that allows the compression process to take place and ensure there is only vertical movement. Further, the weight block ensures the system can utilize gravitational force on the downstroke. Further, the plurality of outtakes allows for the gas or fluids to flow out of the system once compressed or pumped. Furthermore, the conical tank takes the compressed gas or pumped fluid and further compresses the gas, increasing the pressure without moving parts. Thus, the device operates on carbon free electricity to compress gas and pump fluids.

A pump for pumping a cryogenic liquid includes a pump housing having a cylinder with a piston slidably positioned therein. An intermediate fluid chamber that receives an intermediate fluid is defined within the cylinder adjacent to a first end of the piston and a fluid pumping chamber is defined within the cylinder adjacent to a second end of the piston. An intermediate fluid seal is attached to the piston and engages the cylinder. A pumped fluid seal attached to the piston and configured to engage the cylinder, said pumped fluid seal spaced from the intermediate fluid seal so that a differential pressure space is defined within the cylinder between the intermediate fluid and pumped fluid seals. A differential pressure vent valve is in fluid communication with the differential pressure space. A differential pressure switch senses a pressure within the differential pressure space and opens the differential pressure vent valve when the pressure within the differential pressure space reaches a predetermined pressure level.

A bypass plunger combines a unitary or one-piece hollow body-and-valve cage, retains a dart valve within the valve cage portion of the hollow body using a threaded retaining nut secured by crimple detents. A series of helical grooves surround the central portion of the outer surface of the hollow body of the plunger to control spin during descent. A canted-coil-spring disposed within the retaining nut functions as a clutch. The valve cage includes ports that may be configured to control flow through the plunger during ascent. Other embodiments include clutch assemblies using canted-coil springs with split bobbins, and valve stems surfaced to achieve specific functions. Combinations of these features provide enhanced performance, durability and reliability at reduced manufacturing cost, due primarily to the simplicity of its design.

A piston is described for the compression of a pneumatic fluid in a compression chamber of a cylinder comprising: a cylindrically shaped piston body, adapted to be arranged slidably within said cylinder, and having a side wall and a top wall; along a circumferential perimeter of said side wall of the piston body a seat being defined; and a sealing assembly accommodated in said seat, and adapted to ensure the fluid-tightness along said circumferential perimeter; the sealing assembly comprising a plurality of sealing elements, having shapes complementary to one another, and configured so that the wear of a sealing element along said circumferential perimeter corresponds to a sliding in the radially outer direction of the adjacent sealing element.

Piston ring arrangement (40) with a piston ring (50) encircling a main axis (X), the piston ring (50) having a sealing surface (58) directed radially outward and a contact surface (55) directed radially outward, the sealing surface (58) being radially outside of the contact surface (55). To improve the service life of piston rings for reciprocating compressors, the piston ring arrangement (40) has a retaining ring (70) encircling the main axis (X) with a retaining surface (72) directed radially inward, the piston ring (50) and the retaining ring (70) being situated such that the retaining surface (72) and the contact surface (55) are adjacent in the radial direction.

The present invention relates to a device for dispensing liquid product, comprising a fixed part and a moving part; the fixed part comprising an intake orifice, a delivery orifice, a body comprising a cavity into which said orifices open, said cavity being able to partially house the moving part, the remaining volume forming an emptying chamber; the moving part being able to move partially in the cavity of the fixed part and comprising a piston, a piston driving element, an axial spring, a duct extending along the circumference of the piston, said duct allowing positions that allow fluidic communication between the emptying chamber and just one of said orifices and allowing switchover positions in which all fluidic communication between the emptying chamber and each of said orifices is forbidden, a cam able to convert the rotation of the drive element into an oscillatory-rotary movement of the piston. The axial spring is able to absorb energy during a liquid intake phase and to restore same during a liquid delivery phase, said spring being positioned around the piston which is on the moving part situated inside the cavity of the body.