活塞滑阀

solid-skirt piston

moisture separation in the reciprocating-piston pump

piston with inserted ring carrier

oscillating-piston pump

intermeshing engagement and intermeshing engagement in rotary-piston machines or engines

combination of rotary-piston pumps with oscillating-piston pumps

hydrostatic engines of reciprocating-piston type with

differential pump (stepped-piston pump)