Assertion: engine's valve | /r/CapableOf | control both steam flows
Facets:
value: usually
type: TEMPORAL
Source sentences:
text: However, as one and the same valve usually controls both steam flows, a short cutoff at admission adversely affects the exhaust and compression periods which should ideally always be kept fairly constant; if the exhaust event is too brief, the totality of the exhaust steam cannot evacuate the cylinder, choking it and giving excessive compression ("kick back").