Vertical movement of the plunger actuates a cam or screw to vary {HEAD ~ the setting} of the control element of {TAIL ~ the level control system} 
Vertical movement of the plunger actuates a cam or screw to vary { HEAD ~ the setting } of the control element of { TAIL ~ the level control system }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL