Seeking help with the Autopipe issue
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This post was last edited by strongerlihe on 2010-3-17 at 15:08. 1. According to the specifications, the unrolled length of the pipe between the supports at both ends of a 90° elbow should not be greater than 0.7 times the standard span. What is the constraint on the expanded length of the pipeline if there are two 90° elbows between two supports? Should it be less than 0.7 times the standard span, or less than 0.7X0.7=0.49 times the standard span? 2. When determining the standard span for steam pipes, is it based on the weight of steam or the weight of water? If it is determined based on the weight of steam, then how can the strength of the pipes be ensured during hydrotesting? 3. How are the stress increase factors for special components such as elbows and tees reflected in Autopipe? Or when displaying the stress analysis results, has the software already taken the stress increase factor into account? 4. If two rigid hangers are installed on a vertical pipe section, how can the distribution of the pipe section’s weight be ensured during installation? 5. How does Autopipe verify the stiffness conditions for the spacing of supports and hangers?
It’s just my personal opinion; it might be wrong. For reference only: 1. “According to the standard, the expanded length of the pipe between the supports at both ends of a 90° elbow is …” This standard does not specify whether it refers to one elbow or multiple elbows; therefore, I believe that it is sufficient if the expanded length of the pipe meets the 0.7 requirement. (The technical specification for the design of steam and water pipelines in power plants is 0.73.) 2. “When determining the standard span for steam pipelines, should it be based on the weight of steam or the weight of water...?” ” I think this one should be calculated based on the weight of the water. The loads taken into account in the design of supports and hangers are not only those during operation; other factors such as hydraulic testing must also be considered. 3. I have never used Autopipe. Different clearly! However, the stress enhancement factor of the fittings can be entered in other stress calculations. 4. If two rigid hangers are installed on a vertical pipe section, how can the distribution of the pipe section’s weight be ensured during installation? I’m not quite sure what the original poster means How does installation ensure weight distribution? The weight distribution is calculated based on the pipe layout. Rigid hangers are installed in vertical pipes at positions determined by the design. There shouldn’t be much to worry about regarding installation. 5. How does Autopipe verify the stiffness conditions for the spacing of supports and hangers? This is not clear.
1. The overall span, including the elbows, is intended to assist piping designers. For experienced stress engineers, this span should be determined based on their expertise or calculations, as well as the project specifications. 2. For steam lines, the span must take into account the fact that the pipes are filled with water, due to the presence of condensate. The criteria for pressure testing differ from those used to determine the stresses resulting from expansion or other factors. According to ASME 31.3, the stress applied during hydrotesting is…
Thank you to all for your replies; these issues are now clear.
Hmm, I was studying* and referred to it; thanks for sharing