Therefore, {HEAD ~ negative pressure} is alternately produced in {TAIL ~ the low pressure chamber} 28 and in the low pressure chamber 35 communicating, respectively, with the pump working chambers 14, 14 
is alternately produced in
Therefore , { HEAD ~ negative pressure } is alternately produced in { TAIL ~ the low pressure chamber } 28 and in the low pressure chamber 35 communicating , respectively , with the pump working chambers 14 , 14
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH