Chapter III Materials
423 MATERIALS ?? GENERAL REQUIREMENTS Steel pipe designed to be operated at a hoop stress of more than 20% SMYS shall be impact tested in accor- dance with the procedures of supplementary require- 423.1 Acceptable Materials and Specifications ment SR5 of API 5L, or ASTM A333. The test temperature shall be the lower of 32??F (0??C) or the lowest expected
(a) The materials used shall conform to the specifica- metal temperature during service, having regard to past
tions listed in Table 423.1-1 or shall meet the require- recorded temperature data and possible effects of lower ments of this Code for materials not listed. Specific
air and ground temperatures. The average of the Charpy editions of standards incorporated in this Code by refer-energy values from each heat shall meet or exceed the ence, and the names and addresses of the sponsoring following:
organizations, are shown in Mandatory Appendix I, since it is not practical to refer to a specific edition of (a) For all grades with an SMYS equal to or greater
each standard in Table 423.1-1 and throughout the Code than 42,000 psi (289 MPa), the required minimum aver-text. Mandatory Appendix I will be revised at intervals, age (set of three specimens) absorbed energy for each
as needed, and issued in Addenda to the Code. Materials heat based on full-sized (10 mm 10 mm) specimens and components conforming to a specification or stan- shall be 20 lb-ft (27 J) for transverse specimens or
dard previously listed in Table 423.1-1, or to a super- 30 lb-ft (41 J) for longitudinal samples.
seded edition of a listed specification or standard, may (b) For all grades with an SMYS less than 42,000 psibe used. (289 MPa), the required minimum average (set of three
(b) Except as otherwise provided for in this Code, specimens) absorbed energy for each heat based on full-materials that do not conform to a listed specification sized (10 mm 10 mm) specimens shall be 13 lb-ft (18 J).
or standard in Table 423.1-1 may be used provided they 423.2.4 Cast, Malleable, and Wrought Iron conform to a published specification covering chemistry,
(a) Cast, malleable, and wrought iron shall not be physical and mechanical properties, method and process used for pressure-containing parts except as provided
of manufacture, heat treatment, and quality control, and
in paras. 407.1(a) and (b), and para. 423.2.4(b).otherwise meet the requirements of this Code. Allowable
stresses shall be determined in accordance with the (b) Cast, malleable, and wrought iron are acceptable
applicable allowable stress basis of this Code or a more in pressure vessels and other equipment noted in
conservative basis. para. 400.1.2(b) and in proprietary items [see
para. 400.1.2(g)], except that pressure-containing parts
shall be limited to pressures not exceeding
(12) 423.2 Limitations on Materials 250 psi (17 bar).
423.2.5 Materials for Liquid Anhydrous Ammonia
423.2.1 General Pipeline Systems. Only steel conforming to specifica-
(a) The designer shall give consideration to the signif- tions listed in Mandatory Appendix I shall be used for icance of temperature on the performance of the pressure-containing piping components and equipment material. in liquid anhydrous ammonia pipeline systems. How-
(b) Selection of material to resist corrosion, erosion, ever, internal parts of such piping components and and other deterioration in service is not within the scope equipment may be made of other materials suitable for of this Code. It is the designer??s responsibility to select the service.
materials suitable for the fluid or slurry service under The longitudinal or spiral weld of electric resistance the intended operating conditions. An example of a welded and electric induction welded pipe shall be source of information on materials performance in corro- normalized.
sive environments is the Corrosion Data Survey published Cold formed fittings shall be normalized after by the National Association of Corrosion Engineers. fabrication.
Except for the quantities permitted in steels by indi-
423.2.3 Steel. Steels for pipe are shown in vidual specifications for steels listed in Mandatory
Table 423.1-1 (except as noted in para. 423.2.5). Appendix I, the use of copper, zinc, or alloys of these Download ASME B31.4