In the absence of an open configuration of {TAIL ~ the second valve apparatus, fluid pressure increases} in {HEAD ~ the second flow path} 
In the absence of an open configuration of { TAIL ~ the second valve apparatus , fluid pressure increases } in { HEAD ~ the second flow path }
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD