The system also includes {TAIL ~ a pressure differential switch} which senses {HEAD ~ a drop} in pressure across a pedal valve 
The system also includes { TAIL ~ a pressure differential switch } which senses { HEAD ~ a drop } in pressure across a pedal valve
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH