Document: NRC Regulatory Guide
Document ID: 1d715751-9321-4481-a46f-4ff802a5efe0
Document Type: regulatory_guide
Title: Service Limits and Loading Combinations for Class 1 Linear-Type Supports + HISTORY – HISTORY 10/2006 – DG-1168 , Proposed Revision 2
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0630/ML063000449.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.124
CFR Part: 
CFR Title: 

Content:
for a net section, as specified in NF-3322.1(a)(1) of Section III, should be the lesser of two values, 0.6Sy or 0.5Su, at temperature. For net sections at pinholes in eyebars, pin-connected plates, or built-up structural members, Ft as specified in NF-3322.1(a)(2) should be the lesser of two values, 0.45Sy or 0.375Su, at temperature. b. The shear stress limit Fv for a gross section, as specified in NF-3322.1(b)(1) of Section III, should be the lesser of two values, 0.4Sy or 0.33Su, at temperature. c. The bending stress limit Fb resulting from tension and bending in structural members, as specified in NF-3320, should be (1) the lesser value of 0.66 Sy or 0.55 Su, at temperature, for compact sections, (2) the lesser value of 0.75 Sy or 0.63 Su, at temperature, for doubly symmetrical members with bending about the minor axis, and (3) the lesser value of 0.6 Sy or 0.5 Su, at temperature, for box-type flexural members and miscellaneous members. Many of the limits and equations for compression strength specified in NF-3320 have built-in constants based on Young’s Modulus of 29,000 kips per square inch (Ksi). For materials with Young’s Modulus at working temperatures substantially different from 29,000 Ksi, these constants need to be rederived with the appropriate Young’s Modulus unless the conservatism of using these constants as specified is demonstrated. 3. Component supports designed by linear-elastic analysis may increase their Level A or B service limits according to the provisions of NF-3321.1(a) of Section III of the ASME Code. F-1334 permits an increase of Level A or B service limits for Level D service limits by the lesser factor of 2 or 1.167Su/Sy if Su > 1.2Sy, or 1.4 if Su # 1.2Sy, where Sy and Su are component-support material properties at temperature. However, all increases (i.e., those allowed by NF-3321.1(a) and F-1334) should always be subject to the limits in NF-3321.1(b). Material properties at temperature should be used to calculate the critical