Document: NUREG-0800
Document ID: 85a8d3b1-a30b-4282-8217-8bc68986145a
Document Type: srp
Title: ASME CODE CLASS 1, 2, AND 3 PIPING SYSTEMS, PIPING COMPONENTS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1404/ML14042A513.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.12
CFR Part: 
CFR Title: 

Content:
d with methods specific to the design of these components. The evaluation typically consists of iterative response spectra analyses of the piping and support system. The analyses will be reviewed on a case by case basis to ensure the response of the specific devices is addressed. vi. Use of Snubbers The acceptance criteria provided in SRP Section 3.9.3, Subsection II.3 are applicable. vii. Pipe Support Stiffness The acceptance criteria provided in SRP Section 3.9.3, Subsection II.3 are applicable. viii. Seismic Self-Weight Excitation The acceptance criteria provided in SRP Section 3.9.2, Subsection II.2.A, are applicable for evaluating loads caused by the seismic excitation of the pipe support. 3.12-13 Revision 1 – April 2014 ix. Design of Supplementary Steel The design of structural steel for use as pipe supports should comply with the ASME Code, Section III, Subsection NF. x. Consideration of Friction Forces The design of sliding type supports, such as guides or box supports, should include evaluation of the friction loads induced by the pipe on the support (e.g., during thermal expansion of the piping). The applicant should provide the friction coefficients used in the evaluation. xi. Pipe Support Gaps and Clearances Small gaps are generally provided for frame type supports. The gap allows for radial thermal expansion of the pipe and for pipe rotation. This gap must account for the diametrical expansion of the pipe due to temperature and pressure. The acceptance criteria for the gap and clearance size (total of opposing sides) between the pipe and the support will be reviewed on a case by case basis depending on the specific pipe diameter, temperature, and pressure in the design, as well as expected piping displacement. For example, large-diameter piping systems may justify a 0.125-inch gap, but smaller-diameter piping systems will need smaller gaps to provide adequate support. xii. Instrumentation Line Support Criteria The acceptance criteria provided in ASME