On the ASME Form U-1 (Manufacturer’s Data Report for Pressure Vessels), the information regarding Postweld Heat Treatment (PWHT) is typically found in Line 14.
The U-1 form is structured to categorize the vessel’s components. For a standard vessel, check the following:
Line 14 (Shell): This line usually contains a sub-section or column labeled “Postweld Heat Treatment.” * It will specify the Temperature and the Time (duration) the shell was held at that temperature. If no PWHT was performed, it may say “None” or “N/A.”
Line 15 (Heads): If the heads required a different heat treatment or were treated separately, this information is recorded here in a similar format (Temp/Time).
Line 21 (Remarks): If the PWHT was partial, applied only to certain welds, or performed under a specific exemption (like those found in UCS-56), the manufacturer will often include detailed notes in the Remarks section.