In the normal operation of the pump turbine apparatus in the turbine or pump operation mode, {HEAD ~ the fail safe valve} 47 is held at {TAIL ~ the illustrated position} by the force of a spring associated therewith 
is held at
In the normal operation of the pump turbine apparatus in the turbine or pump operation mode , { HEAD ~ the fail safe valve } 47 is held at { TAIL ~ the illustrated position } by the force of a spring associated therewith
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 OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH