{HEAD ~ Movement} of the shaft and vent follower continues until the pressure between {TAIL ~ the two cells} is equalized and the vent follower is once again in direct relation to the vent 
{ HEAD ~ Movement } of the shaft and vent follower continues until the pressure between { TAIL ~ the two cells } is equalized and the vent follower is once again in direct relation to the vent
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH