The magnitude of the extra rotation of said motor has to be set to {HEAD ~ a value} which reliably covers {TAIL ~ at least the possible tolerances} of said valve element and any slacks within the force transmission path between the motor and the valve element 
The magnitude of the extra rotation of said motor has to be set to { HEAD ~ a value } which reliably covers { TAIL ~ at least the possible tolerances } of said valve element and any slacks within the force transmission path between the motor and the valve element
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL 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