Reduced bore couplings and adaptors for pressures up to 100 lb/sq in. Whitworth (B.S.P.) threads to BS 84 and American threads to ASA specification B.33.1 ( in to 2 in) and Federal Standard ZZ-H-466b (November 1935)(2 in to 4 in). Details of American threads. Compatible with oil equipment to API Std 5L and 6A. Materials, dimensions, workmanship, marking, hydrostatic testing. Illustrations with full dimensions.