We carry an extensive inventory of 150 lb stainless steel cast unions and stainless steel socket weld unions in many grades and multiple sizes. We can accommodate any need with our wide-ranging and hard to find sizes. View our stainless steel products line card. Our pipe sizes and weights chart will help you search individual product specifications. Unions generally meet ASA B16.3 and pipe threads conform to ASA B2.1 standard for manufacturing. View the standard specifications chart. View the various grades of stainless steel. View thousands of stainless steel pipe and tubing products including our 150# unions and various custom fabrication services Shaw Stainless offers. This Reference Catalog identifies stainless steel pipe unions and other stainless steel pipe fittings with specification charts and illustrations. View the theoretical bursting pressures for various stainless steel pipe. A union is a pipe fitting designed for an easy connection and disconnection for future pipe maintenance and replacement. It is similar to the coupling but a coupling requires more work to disconnect and remove from the piping system. Unions feature a three-part configuration consisting of a male end, a hex nut and a female end.