Assertion: positive displacement compressor | /r/HasProperty | the reciprocating piston type
Facets:
value: usually
type: TEMPORAL
Source sentences:
text: Positive displacement compressors are usually of the reciprocating piston type, in which the gas is drawn in during the suction stroke of the piston, compressed by decreasing the volume of the gas by moving the piston in the opposite direction, and, lastly, discharged when the gas pressure exceeds the pressure acting on the outlet valve.