Flexibility analysis: criteria for cryogenic piping
Flexibility analysis: criteria for cryogenic piping
(OP)
Besides the (obvious) minimum requirements per ASME B31.3, can anyone please provide me with some good general practice,
background reading or sources that elaborate on (piping design but more specifically) flexibility analysis for cryogenic piping service?
For example,
- PIP PNC0004 shows a graph that when T < -100 deg C, formal analysis is required (or comprehensive analysis when T < -155 deg C).
- other eng-tips topic (e.g. #268753) note that there are other rules of thumb for determining whether or not formal or comprehensive
analysis may be required, e.g. the 1500-rule (NPS x temp in F), the ASME para 319.4 'rule', etc ... But they mostly deal with 'hot' piping.
- there's a book by Nayyar, with a specific chapter on cryogenic piping (but I don't have the book, right now).
Any other suggestions/resouces/readings?
Note; the coldest service deals mostly with NPS <= 4, temperatures up to -196 C and AISI316 material.
background reading or sources that elaborate on (piping design but more specifically) flexibility analysis for cryogenic piping service?
For example,
- PIP PNC0004 shows a graph that when T < -100 deg C, formal analysis is required (or comprehensive analysis when T < -155 deg C).
- other eng-tips topic (e.g. #268753) note that there are other rules of thumb for determining whether or not formal or comprehensive
analysis may be required, e.g. the 1500-rule (NPS x temp in F), the ASME para 319.4 'rule', etc ... But they mostly deal with 'hot' piping.
- there's a book by Nayyar, with a specific chapter on cryogenic piping (but I don't have the book, right now).
Any other suggestions/resouces/readings?
Note; the coldest service deals mostly with NPS <= 4, temperatures up to -196 C and AISI316 material.





RE: Flexibility analysis: criteria for cryogenic piping
RE: Flexibility analysis: criteria for cryogenic piping
What the fluid does to the pipe. That might be thermal shock, flow induced vibration, pressure both static and fluctuating etc.
What the pipe does to the world ... what it is connected to / resting on, load limitations etc.
What the world does to the pipe ... imposed forces, displacments, vibration etc.
The second two are common to any pipe, hot or cold. The first is where major differences lie for cryo systems, in terms of brittle failure risk, icing of supports etc., and needs particular consideration. As regards, the specific need for comprehensive (computer based like Caesar II) stress analysis, these days it is economic to err on the safe side.
RE: Flexibility analysis: criteria for cryogenic piping
Do you have any references/sources (i.e. books) which may cover
methods for thermal shock, flow induced vibration, pressure both static and fluctuating etc.?
RE: Flexibility analysis: criteria for cryogenic piping
It's an excellent resource.
RE: Flexibility analysis: criteria for cryogenic piping