{HEAD ~ The valve} is closed by swinging {TAIL ~ the valve element} through 90 degrees thus moving the valve element passage out of registry with the ports 13 13 of the chamber 
is closed by swinging
{ HEAD ~ The valve } is closed by swinging { TAIL ~ the valve element } through 90 degrees thus moving the valve element passage out of registry with the ports 13 13 of the chamber
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH