scope:

INTRODUCTION

In ASME BPVC Section VIII Division 1, the yield strength (Sy) is used directly, or indirectly through the allowable primary and secondary stress limit (SPS = max [3S, 2Sy]), and in many of the design rules, such as:

(a) UG-28 and UG-33 - External pressure: Calculation of allowable external pressure on cylinders and heads - Sy [see UG-28(c)(2) Step 3]

(b) Part UHX - Shell-and-tube heat exchangers: Secondary stress limit in tube sheets, channels, shells, and expansion joints - SPS 27 October 2015 Page 2 of 6

(c) Part UHX - Fixed tube sheet heat exchangers: Allowable tube buckling stress at design temperature - Sy

(d) Appendix 1-4 - Design of Head: Yield strength at design temperature - Sy

(e) Appendix 1-5 and 1-8 - Conical Reducers: Discontinuity stress limit and operating metal temperature - SPS

(f) Appendix 5 - Flanged-and-Flued and Flanged-Only Expansion Joints: Thermally induced stress limit at operating metal temperature - SPS

(g) Appendix 13 - Noncircular Vessels: Plate buckling stress at design temperature

(h) Appendix 26 - Bellows Expansion Joints: Calculation of instability due to internal pressure at design temperature - Sy

(i) Non-mandatory Appendix A - Tube-to-Tube sheet Joint Loads: Calculation of tube joint interface pressure at the operating metal temperature - Sy

Because Table Y-1 provides yield strength values up to 1000°F maximum, yield strength values up to the maximum temperature design are needed.

Due to the large number of missing values, the materials investigated will be restricted to the list below, which correspond to the most commonly used materials for heat exchangers.