Abstract: ON THE MORNING OF AUGUST 1, 1991, TWO INJURY ACCIDENTS OCCURRED INSIDE A HOSPITAL CENTRAL UTILITY PLANT. EMPLOYEE #1 WAS INJURED AT 9:50 A.M. WHEN THE CAP ON A PARTIALLY PRESSURIZED 5-GALLON POT FEEDER TANK FLEW OFF AND THE EMPLOYEE WAS SPRAYED WITH HOT WATER AND ANTI-CORROSIVE CHEMICALS FROM THE TANK, WHICH IS PART OF THE DOMESTIC HOT WATER SYSTEM. HE HAD JUST SERVICED THE TANK (ADDED CHEMICALS) AND TAPPED THE TWIST-ON CAP TO STOP A SMALL LEAK. THE CAP REACHED A SECOND RELEASE POINT AND FLEW OFF UNDER PRESSURE. THE SYSTEM HAD NO TURN LIMITING DEVICE FOR THE CAP, SUCH AS A STOP PIN. AT 11:20 AM., EMPLOYEE #2 SUFFERED SIMILAR INJURIES WHEN THE SAME CAP FLEW OFF AS HE TAPPED IT TO TRY TO STOP THE LEAK AFTER MAKING SOME ADJUSTMENTS TO THE CAP SEAL (GASKET).