A valve assembly includes a seat plate having a top surface and a bottom surface, a plurality of first valve modules arranged in a first level relative to the seat plate such that a first seating face of each of the plurality of first valve modules is substantially co-planar with a first plane that is substantially parallel to at least one of the top surface and the bottom surface of the seat plate, and at least one second valve module arranged in a second level relative to the seat plate such that a second seating face of the at least one second valve module is co-planar with a second plane that is substantially parallel to the first plane, wherein the second plane is offset from the first plane by a first distance.

Reciprocating-type compressor for refrigeration and/or conditioning and/or heat pump systems, comprisinga casing in which there is defined at least one compression section comprising at least one cylinder and a corresponding compression piston, a head provided on said casing, defining a delivery chamber immediately down-stream of said compression section, and adapted to receive the compressed fluid from said compression section, an intake zone from where the fluid to be compressed in the at least one cylinder of said compression section is introduced, a delivery tap at the operational outlet of said compression chamber, characterized in that it comprises a check valve placed between said operational outlet of said compression chamber and said delivery tap, adapted to prevent the return of fluid into the compression chamber from said delivery tap.

A valve for controlling fluid flow, the valve comprising: a first plate comprising a plurality of first holes extending through said first plate; a second plate comprising a plurality of second holes extending through said second plate, the second holes being substantially offset from the first holes of said first plate; wherein said first plate and said second plate are arranged to form a cavity therebetween in fluid communication with the first holes of said first plate and the second holes of said second plate; and a flap disposed and moveable between said first plate and said second plate, said flap having holes substantially offset from the first holes of said first plate and substantially aligned with the second holes of said second plate; wherein said flap is operable to be motivated between said first and second plates in response to a change in direction of differential pressure of the fluid across the valve; wherein said first plate comprises a coating disposed on a surface of the first plate; wherein the first plate comprises a plurality of clearance regions, substantially aligned with the holes of the flap, in which a thickness of the coating is reduced; and wherein each of the clearance regions defines a respective inner region in which a thickness of the coating is generally greater than its defining clearance region.

An illustrative example embodiment of a compressor assembly includes a compressor housing having a suction inlet and a discharge outlet. A flow restricting valve allows unrestricted fluid flow in a first direction into the housing through the suction inlet and out of the discharge outlet during a first operating condition. The flow restricting valve allows a restricted fluid flow in a second, opposite direction into the housing through the discharge outlet in a second operating condition.

A pneumatically driven piston pump and its quick exhaust slide valves, which allows air to be evacuated from the piston pump's piston chambers directly into the environment without having to pass through the main distributor valve, in such a way that it does not cause a drop in temperature due to the expansion of the compressed air which freezes the humidity of the air itself, clogging the compressed air circulation ducts and causing the pump to shut down or stall. Such an air-operated piston pump with quick exhaust valves allows the passage of air with low restriction, which increases the efficiency of the piston pump and decreases its compressed air consumption compared to the same air motor without quick exhaust valves.