{HEAD ~ a high pressure port} and a low pressure port in {TAIL ~ fluid communication} with said valve lands on opposed axial sides of said seal assembly 
in
{ HEAD ~ a high pressure port } and a low pressure port in { TAIL ~ fluid communication } with said valve lands on opposed axial sides of said seal assembly
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH