A mechanically actuated traveling valve for use in fluid pumping equipment is provided. More particularly, a mechanically actuated traveling plug valve having a valve seat and a valve plug is provided for use in any positive displacement pump with a reciprocating element (either the plunger or the cylinder) capable of pumping fluids of any viscosity, with any gas to liquid ratio, operating at any inclination angle.

A piston for a single-stroke pump includes a pump rod, a seal ring extending about the pump rod and having a central bore, and a retaining device disposed on the pump rod and retaining the seal ring on the pump rod. In a forward stroke, the seal ring is in a first position whereby the seal ring sealingly engages the pump rod such that the seal ring and pump rod drive a fluid out of the pump chamber. When transitioning to a return stroke, the seal ring is maintained stationary relative to the pump cylinder until retaining device engages seal ring, such that seal ring is in a second position. With the seal ring in the second position, a flow path is opened between the seal ring and the pump rod, allowing fluid to flow into the pump chamber to prime the pump the next pump cycle.

A mechanically actuated traveling valve for use in fluid pumping equipment is provided. More particularly, a mechanically actuated traveling plug valve having a valve seat and a valve plug is provided for use in any positive displacement pump with a reciprocating element (either the plunger or the cylinder) capable of pumping fluids of any viscosity, with any gas to liquid ratio, operating at any inclination angle.

A piston for a single-stroke pump includes a pump rod, a seal ring extending about the pump rod and having a central bore, and a retaining device disposed on the pump rod and retaining the seal ring on the pump rod. In a forward stroke, the seal ring is in a first position whereby the seal ring sealingly engages the pump rod such that the seal ring and pump rod drive a fluid out of the pump chamber. When transitioning to a return stroke, the seal ring is maintained stationary relative to the pump cylinder until retaining device engages seal ring, such that seal ring is in a second position. With the seal ring in the second position, a flow path is opened between the seal ring and the pump rod, allowing fluid to flow into the pump chamber to prime the pump the next pump cycle.

A double-acting refrigerant compressor includes a piston freely guided on two cylinder portions arranged opposite to each other and being immobile relative to each other. The piston includes a flow channel extending internally through the piston. Each cylinder portion and the piston include, along the flow channel, respectively at least one back-check valve. The back-check valves are arranged in such a manner that their flow directions are unidirectional.

A double-acting refrigerant compressor includes a piston freely guided in a fixed mounted cylinder. The cylinder includes an inlet valve plate having an inlet valve. The piston includes a flow channel extending internally through the piston. The flow channel of the piston includes at least one back-check valve being arranged with a unidirectional flow. The piston includes a second cylinder portion within which is guided over a fixed mounted inverse piston. The inverse piston includes an inverse piston flow channel with an outlet valve in fluid communication with a volume within the second cylinder portion. Alternative embodiments include a piston with interior cylinders where the piston is guided over the two inverse pistons.