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 the illustrated position by {TAIL ~ the force} of a spring associated therewith 
is held by
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 the illustrated position by { TAIL ~ 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 OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH