Below is a list of ASME Pressure Vessels manufacturers from Waukesha, Wisconsin. ASME pressure vessels are approved in all aspects and regularly inspected by the American Society of Mechanical Engines. ASME is an engineering board that sets codes and standards for mechanical devices to improve their safety and prevent deadly and costly accidents. The codes and standards for high pressure vessels set by ASME consist of three different divisions, which are based on psi level.