Blank Cap 3 : A metal casting used fro shutting off an inlet or an outlet such as the delivery on a pump or the inlet on a collecting head when not in use. Larger blank caps are made to shut off the suction inlet on a pump
H. J. Porter (Chairman - Technical Committee), Dictionary of Fire Technology, The Institution of Fire Engineers, The Victory Press (Leicester) Ltd. 1979 UK. (Fr Tech - Brit) {81}