The actuator includes {HEAD ~ a first piston} slidably mounted in an actuator housing, and a second piston, attached to {TAIL ~ the valve pin}, slidably mounted within the first piston 
The actuator includes { HEAD ~ a first piston } slidably mounted in an actuator housing , and a second piston , attached to { TAIL ~ the valve pin } , slidably mounted within the first piston
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH