Section II Part D Properties (Metric) Materials
MANDATORY APPENDIX 2 BASIS FOR ESTABLISHING DESIGN STRESS INTENSITY VALUES FOR TABLES 2A, 2B, AND 4, AND ALLOWABLE STRESS VALUES FOR TABLE 3
2-120 CRITERIA FOR BOLTING
MATERIALS IN TABLE 3 FOR USE WITH SECTION III (CLASS 2 AND 3 RULES); SECTION VIII, DIVISION 1; SECTION VIII, DIVISION 2 (PART 4.16 RULES); AND
SECTION XII
(a) For materials whose strength has not been enhanced by heat treatment or by strain hardening, the allowable stress value shown at any temperature in Table 3 is the least of the following:
(1) one-fourth of the specified minimum tensile strength at room temperature
(2) one-fourth of the tensile strength at temperature
(3) two-thirds of the specified minimum yield strength at room temperature
(4) two-thirds of the yield strength at temperature
(b) For materials whose strength has been enhanced by heat treatment or by strain hardening, the allowable stress value shown at any temperature in Table 3 is the least of the following, unless these values are lower than the annealed values, in which case the annealed values shall be used:
(1) one-fifth of the specified minimum tensile strength at room temperature
(2) one-fourth of the tensile strength at temperature
(3) one-fourth of the specified minimum yield strength at room temperature
(4) two-thirds of the yield strength at temperature
(c) In the application of these criteria, the Committee considers the yield strength at temperature to be SYRY , and the tensile strength at temperature to be 1.1STRT.
(d) At temperatures in the range where creep and stress rupture strength govern the selection of stresses, the maximum allowable stress value for all materials is established by the Committee not to exceed the lowest of the following:
(1) 100% of the average stress to produce a creep rate of 0.01%/1,000 h
(2) 100F avg % of the average stress to cause rupture at the end of 100,000 h
(3) 80% of the minimum stress to cause rupture at the end of 100,000 h
Stress values for high temperatures are based, whenever possible, on representative uniaxial properties of the materials obtained under standard ASTM testing conditions or equivalent. The stress values are based on basic properties of the materials and no consideration is given for corrosive environment, for abnormal temperature and stress conditions, or for other design considerations.
2-130 CRITERIA FOR BOLTING
MATERIALS FOR USE WITH PART 5 AND ANNEX 5.F OF SECTION VIII, DIVISION 2 AND SECTION III, SUBSECTIONS NB AND WB
The design stress intensity value shown at any temperature in Table 4 is the least of the following, with credit being granted for enhancement of properties by heat treatment or by strain hardening:
(a) one-third of the specified minimum yield strength at room temperature
(b) one-third of the yield strength at temperature
102.3 Allowable Stress Values and Other Stress Limits for Piping Components
102.3.1 Allowable Stress Values
(C) The basis for establishing the allowable stress values in this Code Section are the same as those in the ASME Boiler and Pressure Vessel Code, Section II, Part D, Mandatory Appendix 1; except that allowable stresses for cast iron and ductile iron are in accordance with Section VIII, Division 1, Nonmandatory Appendix P for Tables UCI-23 and UCD-23, respectively.
(a) Bolting Materials. Design stress values at temperature for bolting materials shall not exceed the lowest of the following:
(1) except as provided in (3) below, the lower of one-fourth of specified minimum tensile strength at room temperature (ST) and one-fourth of tensile strength at temperature
(2) except as provided in (3) below, the lower of two-thirds of specified minimum yield strength at room temperature (SY) and two-thirds of yield strength at temperature
(3) at temperatures below the creep range, for bolting materials whose strength has been enhanced by heat treatment or strain hardening, the least of one-fifth of S T , one-fourth of the tensile strength at temperature, one-fourth of SY , and two-thirds of the yield strength at temperature (unless these values are lower than corresponding values for annealed material, in which case the annealed values shall be used)
(4) two-thirds of the yield strength at temperature [see para. 302.3.2(f)]
(5) 100% of the average stress for a creep rate of 0.01% per 1,000 h
(6) 67% of the average stress for rupture at the end of 100,000 h
(7) 80% of minimum stress for rupture at the end of 100,000 h
Notes:
These bases are the same as those for BPV Code, Section III, Class 1 materials, given in Section II, Part D. Stress values in B31.3, Appendix A, at temperatures below the creep range generally are the same as those listed in Section II, Part D, Tables 2A and 2B, and in Table 3 for bolting, corresponding to those bases. They have been adjusted as necessary to exclude casting quality factors and longitudinal weld joint quality factors. Stress values at temperatures in the creep range generally are the same as those in Section II, Part D, Tables 1A and 1B, corresponding to the bases for Section VIII, Division 1.