Optionally, a pressure sensor may be placed on the output side of {TAIL ~ the pump} to provide an indication of an empty reservoir or {HEAD ~ a substantial blockage} in the distribution system  
Optionally , a pressure sensor may be placed on the output side of { TAIL ~ the pump } to provide an indication of an empty reservoir or { HEAD ~ a substantial blockage } in the distribution system
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH