In order to move {HEAD ~ the valve pin} 31 to {TAIL ~ its closed, middle and open positions}, a three position actuator 34 is provided 
In order to move { HEAD ~ the valve pin } 31 to { TAIL ~ its closed , middle and open positions } , a three position actuator 34 is provided
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH