The American Society of Mechanical Engineers (ASME) is a professional engineering society. It is one of the oldest standards-developing organizations in the world. It produces approximately 600 codes and standards.

 

The largest ASME standard is the ASME Boiler and Pressure Vessel Code (BPVC). The BPVC standard provides rules for the design, fabrication, and inspection of boilers and pressure vessels. It is reviewed every three years. The S, U, and U2 stamps are included in the ASME code for defining and certification of pressure vessels.