The valve member substantially prevents {HEAD ~ fluid} from flowing: from the third port to the first port; from the second port to the first port; from the third port to {TAIL ~ the second port}; and directly from the first port to the third port 
from flowing to
The valve member substantially prevents { HEAD ~ fluid } from flowing : from the third port to the first port ; from the second port to the first port ; from the third port to { TAIL ~ the second port } ; and directly from the first port to the third port
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH