EE WAS USING AN 8LB. SLEDGEHAMMER TO OPEN THE PUMP-OFF VALVE ON #54 PPT. AS HE WAS SWINGING THE HAMMER HANDLE STRUCK THE VALVE HANDLE. THIS DEVIATED THE SWING PATTERN. HIS LEFT INDEX FINGER WA S CAUGHT BETWEEN THE HAMMER HANDLE AND THE VALVE HANDLE. THIS CAUSED A LACERATION TO HIS LEFT INDEX FINGER THAT REQUIRED FOUR SUTURES TO CLOSE. NO LOST TIME OR RESTRICTIONS.