B31.8 Compressor Station Replacement of existing lines and required analysis
B31.8 Compressor Station Replacement of existing lines and required analysis
(OP)
Hello All,
If I replace the piping in aa B31.8 compressor station with an exact duplicate of what is currently installed, do I need to perform an new pipe stress analysis?
The reciprocating compressors at this station have been in operation for more than 40 years and the decision has been made to replace the piping due to corrosion damage.
B31.3 has clause 319.4.1(A) Formal Analysis not required "duplicates, or replaces without significant change, a system operating with a successful service record"
B31.8 has paragraph 832.3 Flexibility Requirements "Formal calculations shall be performed where reasonable doubt exists as to the adequate flexibility of the system.
And 833.7 Flexibility Analysis (a)There is no need for a formal flexibility analysis for an unrestrained piping system that (1) duplicates or replaces without significant change a system operating with a successful record.
Are there any other requirements (besides a lack of knowledge of the above clauses) that may drive the requirements for a new analysis?
If I replace the piping in aa B31.8 compressor station with an exact duplicate of what is currently installed, do I need to perform an new pipe stress analysis?
The reciprocating compressors at this station have been in operation for more than 40 years and the decision has been made to replace the piping due to corrosion damage.
B31.3 has clause 319.4.1(A) Formal Analysis not required "duplicates, or replaces without significant change, a system operating with a successful service record"
B31.8 has paragraph 832.3 Flexibility Requirements "Formal calculations shall be performed where reasonable doubt exists as to the adequate flexibility of the system.
And 833.7 Flexibility Analysis (a)There is no need for a formal flexibility analysis for an unrestrained piping system that (1) duplicates or replaces without significant change a system operating with a successful record.
Are there any other requirements (besides a lack of knowledge of the above clauses) that may drive the requirements for a new analysis?
A question properly stated is a problem half solved.
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RE: B31.8 Compressor Station Replacement of existing lines and required analysis
If the system is unrestrained and assuming that a previous stress analysis was performed, then no. If you have no doubt that the system is adequately flexible, then, again, no.
Assuming temperatures and ranges have not changed significantly within recent history (5 yrs), probably no other questions would come to mind.
PS Exactly means exactly.
Reaction to change doesn't stop it
RE: B31.8 Compressor Station Replacement of existing lines and required analysis
1) B31.8 833.7 invokes no requirement that a previous analysis was performed. Merely "duplicates a system with a sucessfull service record". Where does the requirement for an analysis come from?
2) B31.8 does not use the word "exactly" but rather "without significant change". Where does your ps come from?
A question properly stated is a problem half solved.
Always remember, free advice is worth exactly what you pay for it!
http://www.techtran-hou.com/
RE: B31.8 Compressor Station Replacement of existing lines and required analysis
Find what you like to do, earn a living at it, and then make your lifestyle fit your income. — Chuck Yeager
RE: B31.8 Compressor Station Replacement of existing lines and required analysis
A question properly stated is a problem half solved.
Always remember, free advice is worth exactly what you pay for it!
http://www.techtran-hou.com/
RE: B31.8 Compressor Station Replacement of existing lines and required analysis
The P.S. comes from the guy that wrote the B31.3 code. I'm a bit more "flexible" myself.
Find what you like to do, earn a living at it, and then make your lifestyle fit your income. — Chuck Yeager
RE: B31.8 Compressor Station Replacement of existing lines and required analysis
In the conversation with the project team I see a lot of personal opinion, and people hiding from making a decision. If there are regulations dictating requirements for safe operation and that a flexibility analysis is required, by all means point me the chapter and verse of that requirement.... That's why I am asking the question.
A question properly stated is a problem half solved.
Always remember, free advice is worth exactly what you pay for it!
http://www.techtran-hou.com/
RE: B31.8 Compressor Station Replacement of existing lines and required analysis
It doesn't get any clearer than that. If there is any doubt as to adequate flexibility, work out the 3 conditions given in 833.7(a) and 833.7(b) and that should fix you right up. The rest of the story and subsequent requirements will be allowed to develop in due time. Who has any doubts, or who's doubts are important to the result, if unknown at this time may or may not become apparent at a later date.
Find what you like to do, earn a living at it, and then make your lifestyle fit your income. — Chuck Yeager