Power plant safety system

Claim 1

THE COMBINATION IN A POWER PLANT SAFETY SYSTEM COMPRISING A CONTROL HAVING POWER PLANT NORMAL RUNNING AND STOPPING POSITIONS, AN INSTRUMENTALITY SENSITIVE TO THE OCCURRENCE OF AN ABNORMAL CONDITION OF THE POWER PLANT, A SOURCE OF PRESSURED FLUID, MEANS NORMALLY URGING SAID CONTROL TO SAID STOPPING POSITION, MOTOR MEANS OPERATIVELY CONNECTED TO SAID CONTROL, AND A FLUID LINE CONNECTING SAID SOURCE TO SAID MOTOR MEANS, OF A PRESSURE VENTING DEVICE COMPRISING A CASING FORMING A WORKING CHAMBER HAVING SPACED INLET AND VENTING PORTS IN THE WELL THEREOF, A PLUNGER SLIDABLE IN SAID CHAMBER FROM A FIRST POSITION CLOSING COMMUNICATION BETWEEN SAID PORTS TO A SECOND POSITION IN WHICH SAID PORTS ARE IN COMMUNICATION THROUGH SAID WORKING CHAMBER, A FLUID CONNECTION BETWEEN SAID INLET PORT AND SAID FLUID LINE, A VALVE IN SAID CONNECTION, AND MEANS OPERATIVELY CONNECTING SAID VALVE AND SAID CONDITION SENSITIVE INSTRUMENTALITY FOR OPENING SAID VALVE RESPONSIVE TO AN ABNORMALITY OF THE CONDITIONS SENSED BY SAID INSTRUMENTALITY TO EXPOSE SAID INLET PORT AND SAID PLUNGER TO PRESSURE FLUID FROM SAID FLUID LINE AND THEREBY CAUSE SHIFTING OF SAID PLUNGER TO SAID SECOND POSITION WITH RESULTANT VENTING OF SAID FLUID LINE AND SHIFTING OF SAID CONTROL TO SAID POWER PLANT STOPPING POSITION.