The system under consideration was a DHDS plant two-phase piping system with a slug flow operating conditions. The pressures and temperatures were also high. The pipe was SS TP321. Thus it can be treated as a critical system.
In my opinion, the friction forces never disappears from the system. They are always present. Does this means that there is no friction when we are standing on our feet? Friction is always present and the piping system will transfer these friction forces to the connecting equipment nozzle or nearby anchor. In static analysis friction will generally give more conservative results. In the critical systems, including friction in the analysis can significantly change the results of the stress analysis. If the friction forces are going to be disappeared after the thermal reaction, what was the necessity of providing teflon padded supports or roller supports? Why the leading software like CAESAR-II should exclusively add facility of providing friction in the flexibility analysis?
Doesn't it seem logical?
Kaustubh
>>> chrisw@skypoint.com 04/21/03 10:18PM >>>
>A few days ago, a world known consultancy & EPC company suggested us the
>following:
I think that's probably correct, but it may be a matter of judgement in
individual cases. I suspect what usually eliminates friction from gravity
loading is small movements from momentary vibration and thermal movement.
(Small movements that a friend of mine called 'yucking' as in 'The thing
will yuck around a little while it settles in place.')
I suspect individual cases, such as high clamping loads which are likely to be constant over time should be assessed on an individual basis. I've always found that you can seldom depend on friction to do what you want and it'll never do what you need.
Christopher Wright P.E. |"They couldn't hit an elephant at chrisw@skypoint.com | this distance" (last words of Gen. ___________________________| John Sedgwick, Spotsylvania 1864)http://www.skypoint.com/~chrisw
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Received on Tue Apr 22 00:19:00 2003
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