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