Hi,
I come across one case for 42" pipeline which design to comply ASME B31.8. Natural gas inside the line goes through slug catcher so slug flow should not happen. What about effect from high velocity of gas? This is around 460 m/s.(1250 mmSCFD) Can anyone give me some idea? I looked through all topic, there is nothing mentioned about this case.
Many thanks
regards,
W Posri

Hi pw,

I think that you will have no problems during steady operation. Maybe you should check if it is necessary to add forces on elbows, because of change of directions.
There could be unbalance forces during start-up, I would try to model it like Water Hammer analyze.

Caesar manual give example to model the above mention forces.

Best regards,

Sven

Besides the unbalanced thrust load during start up, also look carefully for the stresses in the elbows. Reason being, the high velocity impingement can/will cause erosion corrosion at the elbow, thus resulting in higher stresses in the thinned elbow.I have seen some cases of severe damage of elbow during such high velocity operations.Analysis of the system should not show high stresses in the elbow.

A. Bhattacharya

Stress Analyst

Bechtel Corporation

Thank you for the answer, I also understand that in steady state there should not be a problem. Does anyone have some experience in calculating as a water hammer, and distribute load to the elbow? Or any material to look at, please advise. Actually this line we may decide to put underground at the end, but the case still very interesting to me.
regards,
Waranat