An improved control over the pressure vented or tapped to a back pressure chamber in {HEAD ~ a scroll compressor} is achieved by maintaining a vent hole closed for the majority of {TAIL ~ the operational cycle} of the scroll compressor 
An improved control over the pressure vented or tapped to a back pressure chamber in { HEAD ~ a scroll compressor } is achieved by maintaining a vent hole closed for the majority of { TAIL ~ the operational cycle } of the scroll compressor
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH