The valve member has a first state in which it permits fluid to flow from the first port to the second port and a second state in which it permits {HEAD ~ fluid} to flow from the second port to {TAIL ~ the third port} 
to flow to
The valve member has a first state in which it permits fluid to flow from the first port to the second port and a second state in which it permits { HEAD ~ fluid } to flow from the second port to { TAIL ~ the third port }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL