scope:

This Practice describes the basic requirements for the design, materials, fabrication, examination, inspection, and testing of aboveground, welded, cylindrical shell, single-wall vessels having an internal and external Maximum Allowable Working Pressure (MAWP) not exceeding 15 psig at the top of the vessel in the normal operating position. An additional specification may be required to define options covered herein and other specific requirements considering service (startup, normal operation, upset, shutdown), location, maintenance, etc. The documents listed in Section 2.1 should be used for a complete purchase specification.

This Practice is not intended for flat-bottom tanks or API-type field-erected storage tanks. Unless approved by Purchaser, this Practice is not to be used for low-pressure vessels that will contain "Lethal Substances" as defined in Code Paragraph UW-2 Footnote 1.

Purpose

This Practice provides requirements for the construction of low-pressure, welded vessels that generally must meet the philosophy and requirements of Section VIII, Division 1 of the ASME Boiler and Pressure Vessel Code (Code), but do not require Code inspection or stamping. Vessels may be shop or field fabricated.