The ASME Section VIII, Division 1 philosophy has traditionally relied on the Manufacturer to design pressure vessels based on design conditions provided by the User.

In 2021, revisions to Paragraph U-2(a)(2) expand the circumstances under which the User (or the User's designated agent) must provide formal design requirements that become part of the design basis for the vessel. The intent is to clearly identify design responsibilities whenever the Code alone cannot define all required loading conditions or service requirements. These requirements were intended to improve communication between the User and Manufacturer.