Butt-weld Fitting Standards- ANSI / ASME B16.9, B16.25, B16.28, MSS-SP-43, MSS-SP- 48, MSS-SP-59. Forged Fitting Standards- ANSI/ASME B16.11, MSS-SP-79, MSS-SP-83, MSS-SP-95, MSS-SP-97, BS3799 Sizes- Seamless Butt Weld Fittings Welded Butt Weld Fittings Forged Fittings