A more specific object of the present invention is to provide a bi directional flow control valve with {HEAD ~ substantially identical flow control characteristics} in {TAIL ~ opposite flow directions} 
in
A more specific object of the present invention is to provide a bi directional flow control valve with { HEAD ~ substantially identical flow control characteristics } in { TAIL ~ opposite flow directions }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL