EMPLOYEE WAS BURNING ON A PUG MILL. HE WAS BETWEEN A CHUTE AND THE PUG MILL. HE LIFTED HIS HEAD UP & HIT THE BACK OF HIS HEAD ON THE ACTUATOR OF A PNEUMATIC VALVE THAT WAS MOUNTED ADJACENT TO THE PUG MILL. EE STATED THE PNEUMATIC VALVE IS OUT OF SERVICE & COULD POSSIBLY BE REMOVED.