ASME B31.8a:2000 pdf download

ASME B31.8a:2000 pdf download.MATERIALS AND EQUIPMENT
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.
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 specifi- cation is referenced in this Code, e.g., gas compressor (e) proprietary items (see definition, para. 804.14) (f) unidentified or used pipe
Except for the piping components and structural materials listed in Appendices A and C, it is not intended to include in this Code complete specifications for equipment. Certain details of design and fabrication, however, necessarily refer to equipment, such as pipe hangers, vibration dampeners, electrical facilities, en- gines, compressors, etc. Partial specifications for such equipment items are given herein, particularly if they affect the safety of the piping system in which they are to be installed. In other cases where the Code gives no specifications for the particular equipment item, the intent is that the safety provisions of the Code shall govern, insofar as they are applicable. In any case, the safety of equipment installed in a piping system shall be equivalent to that of other parts of the same system.
(a) Inspection. All pipe shall be cleaned inside and outside, if necessary, to permit good inspection. All pipe shall be visually inspected to determine that it is reasonably round and straight and to discover any defects that might impair its strength or tightness. (b) Bending Properties. For pipe NPS 2 and smaller, a sufficient length of pipe shall be bent cold through 90 deg around a cylindrical mandrel, the diameter of which is 12 times the nominal diameter of the pipe, without developing cracks at any portion and without opening the weld. For pipe larger than NPS 2, flattening tests as pre- scribed in Appendix H shall be made. The pipe shall meet the requirements in this test, except that the number of tests required to determine flattening properties shall be the same as required in subpara. (g) below to determine yield strength. (c) Determination of Wall Thickness. Unless the nominal wall thickness is known with certainty, it shall be determined by measuring the thickness at quarter points on one end of each piece of pipe. If the lot of pipe is known to be of uniform grade, size, and nominal thickness, measurement shall be made on not less than 10% of the individual lengths, but not less than 10 lengths; thickness of the other lengths may be verified by applying a gage set to the minimum thickness. Following such measurement, the nominal wall thick- ness shall be taken as the next commercial wall thickness below the average of all the measurements taken, but in no case greater than 1.14 times the least measured thickness for all pipe smaller than NPS 20, and no greater than 1.11 times the least measured thickness for all pipe NPS 20 and larger. (d) Longitudinal Joint Factor. If the type of longitu- dinal joint can be determined with certainty, the corres- ponding longitudinal joint factor, E (Table 841.115A in Chapter IV), may be used. Otherwise, E shall be taken as 0.60 for pipe NPS 4 and smaller, or 0.80 for pipe larger than NPS 4. (e) Weldability. Weldability shall be determined as follows. A qualified welder shall make a girth weld in the pipe. The weld shall then be tested in accordance with requirements of API 1104. The qualifying weld shall be made under the most severe conditions under which welding will be permitted in the field and using the same procedure as to be used in the field. The pipe shall be considered weldable if the requirements set forth in API 1104 are met. At least one such test weld shall be made for each 100 lengths of pipe on sizes larger than NPS 4. On sizes NPS 4 and smaller, one test will be required for each 400 lengths of pipe. If in testing the weld the requirements of API 1104 cannot be met, the weldability may be established by making chemical tests for carbon and manganese (see para. 823.23), and proceeding in accordance with the provisions of the ASME Boiler and Pressure Vessel Code, Section IX.