WHILE ATTEMPTING TO DISASSEMBLE A HIGH PRESSURE YAMATAKE BACK PRESSURE CONTROL VALVE IN THE INSTRUMENT SHOP, EMPLOYEE SUSTAINED A LACERATION TO HIS HAND. HE WAS TRYING TO PART A CONNECTION THA T JOINS THE TAILPIECE TO THE MAIN VALVE BODY UTILIZING WEDGES TO DO SO. WEDGES BECAM DISLOGED WHEN STRUCK BY A MAUL AND STRUCK HIS HAND.