EMPLOYEE WAS UN-HOOKING A MAG-CHLORIDE DRISCO LINE COUPLING, HE HAD RELEASED THE LATCHES ON THE COUPLING & PULLED ON THE HOSE. THE COUPLING DID NOT RELEASE FROM THE PIPE, THE EE THEN JERKED ON THE HOSE. WHEN THE COUPLING CAME LOOSE, THE COUPLING HIT EE ON THE MOUTH. THIS CUT THE INSIDE OF THE EE'S UPPER LIP. HE WAS TAKEN IN TO THE CLINIC & RECEIVED TWO STITCHES.