scope:

This Practice designates minimum general requirements for the construction of three classes of small pressure vessels (including heat exchangers) with the limited design conditions shown in Table 1. See Section 5.3 for material of construction limitations. This Practice is intended to apply to the Manufacturer's standard, pre-designed pressure vessels and heat exchangers supplied as part of pre-engineered package units (e.g., refrigeration and aircompressor systems), "off-the-shelf" items and vessels (e.g., filters) built from the Manufacturer's standard parts. Use of this Practice for customdesigned vessels is limited to applications that have been reviewed and approved in writing by the Purchaser. Special requirements are covered in the Vessel Specifications (see Section 3 for definition).

Vessels Not Included:

Vessels intended for "Lethal Service" (as defined in the Code)

 Vessels for which design wall thickness would be governed by loadings due to wind pressure or earthquake forces

 Vessels that exceed the limitations of Table 1

Vessels for which shock (thermal or mechanical) and/or cyclical loading is a controlling design requirement and vessels in highly hazardous chemical (e.g., ammonia) service are not permitted to be constructed under Class A requirements (see Table 1).

Many recognized and generally accepted good engineering construction practices are included herein. However, in light of the many diverse service applications of vessels covered under this specification, these practices must be employed with engineering judgment and supplemented as appropriate with requirements related to specific materials of construction, service fluids, operating environments, and vessel geometries. Accordingly, provisions of this Practice may be overridden or supplemented by an Overlay Specification (see Section 3 for definition).

Purpose

This Practice describes the general materials, design, fabrication, examination, inspection, testing, and documentation requirements for pressure vessels with limited design conditions.