ASME B31-8a pdf download CHAPTER I MATERIALS AND EQUIPMENT
810.1 It is intended that all materials and equipment that will become a permanent part of any piping system constructed under this Code shall be suitable and safe for the conditions under which they are used. All such materials and equipment shall be qualified for the conditions of their use by compliance with certain specifications, standards, and special requirements of this Code, or otherwise as provided herein.
811 QUALIFICATION OF MATERIALS AND EQUIPMENT 811.1 Materials and equipment fall into the following six categories pertaining to methods of qualification for use under this Code:
(a) items that conform to standards or specifications referenced in this Code
(b) items that are important from a safety standpoint, of a type for which standards or specifications are referenced in this Code but specifically do not conform to a referenced standard, e.g., pipe manufactured to a specification not referenced in the Code
(c) items of a type for which standards or specifica- tions are referenced in this Code, but that do not conform to the standards and are relatively unimportant from a safety standpoint because of their small size or because of the conditions under which they are to be used
(d) items of a type for which no standard or specification is referenced in this Code, e.g., gas compressor
(e) proprietary items (see definition, para. 804.14)
(f) unidentified or used pipe
811.2 Prescribed procedures for qualifying each of these six categories are given in the following paragraphs.
811.21 Items that conform to standards or specifica- tions referenced in this Code [para. 811.1(a)] may be used for appropriate applications, as prescribed and limited by this Code without further qualification. (See para. 814.)
811.22 Important items of a type for which standards or specifications are referenced in this Code, such as pipe, valves, and flanges, but that do not conform to standards or specifications referenced in this Code [para. 811.1(b)] shall be qualified as described in para. 811.221 or 811.222.
811.221 A material conforming to a written speci- fication that does not vary substantially from a referenced standard or specification and that meets the minimum requirements of this Code with respect to quality of materials and workmanship may be used. This paragraph shall not be construed to permit devia- tions that would tend to affect weldability or ductility adversely. If the deviations tend to reduce strength, full allowance for the reduction shall be provided for in the design.
811.222 When petitioning the Section Committee for approval, the following requirements shall be met. If possible, the material shall be identified with a comparable material, and it should be stated that the material will comply with that specification, except as noted. Complete information as to chemical composition and physical properties shall be supplied to the Section Committee, and their approval shall be obtained before this material is used.
811.23 Relatively unimportant items that do not conform to a standard or specification [para. 811.1(c)] may be used, provided that
(a) they are tested or investigated and found suitable for the proposed service
(b) they are used at unit stresses not greater than 50% of those allowed by this Code for comparable materials
(c) their use is not specifically prohibited by the Code