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