2017530 · MSS SP-43 -2008 Wrought and Fabricated Butt-Welding Fittings for Low Pressure, Corrosion Resistant Applications Standard Practice Developed and Approved by the Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. 127 Park Street, NE Vienna, Virginia 22180 Phone: (703) 281-6613 Fax : (703) 281-6671 Email: