Three-Way Valve Incident - ejected stem during changeout of Duplex Filter

Operation technicians were attempting to change filter banks by operating a three way valve. In act of trying to “loosen” the valve, the pin through the shaft had sheared and the lifting jack nut backed out to the point where the threads were no longer sufficiently engaged. Pressure within overcame any remaining hold on the stem from the packing, and the stem and oil was ejected.