Which pipelines require stress analysis, and are there any national or chemical industry standards specifying this?

GB50316 is already a mandatory international standard. GB/T20801.3 specifies that for pipes with temperatures above 400 degrees and below -70 degrees, stress analysis must be carried out in accordance with the requirements set out therein; it does not define a specific temperature range. For detailed regulations, I recommend checking the Code for Flexible Design of Non-buried Pipelines in Petrochemical Industries.

This post was last edited by yujian_12 on 2010-4-27 at 12:21: 1. Pipelines connected to storage tanks, with a nominal diameter of 12\" or more and a design temperature of 100 degrees or higher. 2. Inlet and outlet pipelines of 3\" and above for centrifugal compressors and reciprocating compressors. 3. Inlet, outlet, and extraction lines of the steam turbine. 4. Suction and discharge pipelines for pumps with a nominal diameter of 4\" or more, operating at temperatures of 100 degrees or above, or below -20 degrees. 5. Inlet and outlet pipelines of air coolers with a nominal diameter of 6\" or more and at a temperature of 120 degrees Celsius or above. 6. Pipelines of 6" or larger connected to the heating furnace outlets and with a temperature of 200 degrees Celsius or higher. 7. A fairly long straight pipe. 8. Pipelines with leaks at the flanges pose a serious hazard. 9. All pipelines with a nominal diameter of 4\" and above, and at temperatures of 100 degrees and above or -50 degrees and below.

This post was last edited by yh8885 on 2010-4-27 at 13:45. What is the standard referred to in the previous comment? Additionally, I could not find any provisions in GB/T20801.3-2006 stating that stress analysis is required for temperatures above 400 degrees or below -70°. Stress analysis is required only as specified in clause 4.1.6.2(e), when the temperature difference between the pipeline installation temperature and the operating temperature is greater than 35°. SH/T3041-2002 Code for Flexible Design of Pipelines A. Operating temperature greater than 400° or lower than -50° ； B. High-temperature pipes entering and exiting the heating furnace or steam generator ； C. High-temperature pipes entering and leaving the reactor ； D. Steam pipes entering and leaving the turbine ； E. Process pipelines leading to and from centrifugal compressors or reciprocating compressors ； F. The pipeline connected to the centrifugal pump can adopt a flexible design method as specified in the design requirements or as shown in the diagram below ； (Images cannot be uploaded; please download the standard documents for reference.) G. Other pipelines whose device connections have special stress requirements ； H. Pipes that require further detailed analysis, as indicated by the simplified analysis method.

What the original poster means is a detailed stress analysis. Theoretically, stress analysis is required for every pipeline, although the analysis for some pipelines can be simplified using methods such as experience. Tang Yongjin’s book cites the provisions of SH 3041 from that brother upstairs. However, Tang also pointed out that specific situations need to be analyzed on a case-by-case basis.

Is stress analysis required for piping work?

This post was last edited by sunnyartboy on 2010-6-22 at 16:04. In principle, any pipeline needs to meet flexibility requirements and undergo stress analysis. However, thanks to years of experience, for pipelines that are relatively simple, have small temperature variations, and low pressures, judgment based on experience is sufficient. Those that are mandatorily required by standards are the more important pipelines – those with large temperature variations or those affecting the outlets of sensitive equipment – as it is difficult to determine such cases based on experience or visual inspection; therefore, for safety reasons, calculations are required. Different design organizations actually have their own sets of rules and principles (Global’s rules are quite good, and they come with experience-based charts as well). When designing pipelines, it is essential to have an overview of stress (flexibility). A responsible engineer, when unsure whether the pipeline being designed has sufficient flexibility, will ask a stress calculation engineer to conduct the relevant calculations (even for pipelines for which calculations are not strictly required). (This is merely my personal opinion for reference only.)

This post was last edited by sunnyartboy on 2010-6-22 at 16:03. Pipeline work and stress analysis complement each other; in short, those who work on pipelines need to understand the principles of (stress) flexibility, but they don’t necessarily have to carry out stress analysis themselves, as different organizations have different divisions of labor: in some organizations, the same person can handle both pipeline work and stress analysis, while in others these tasks are separated. At the same time, those who perform stress analysis also need to have some knowledge of pipeline work, otherwise they may end up with good calculation results that are not practical when it comes to adjusting pipes or supports.

Sh3041 belongs to the category of pipes that require standard stress analysis. Theoretically, stress analysis should be performed on every pipe, but people decide based on experience which pipes do not need it.