Wave action on storage vessels

[ab123456]

We have a number of atmospheric storage tanks at our site by the sea. It is not unusual for waves to come over the sea defences onto site. The question has been asked what would happen in a freak storm and in particular the chances of a wave of such force that it will cause the vessel to rupture.

Does anybody know of any reference that may give some guidance so I can determine the size of wave that would leave a hole in my tank?

 

[IFRs]

Not sure if this helps, but I'd start by figuring out if the tanks will float away after tearing off the inlet and outlet piping.

 

[ab123456]

Thanks IFR, that is indeed another scenario we are considering.

What I am trying to establish is the risk of a release of our material into the sea, a tank is more likely to float away if the tank is empty and if this happens the potential release to environment is small compared to a full tank.

Worst case release would be rupture of a full vessel and i am running out of ideas of how i can calculate the chances of this happening.

 

[owg]

A freak storm with extra high tide can be anticipated with some degree of accuracy. You might then consider the strategy that is used in tank farms which are exposed to threat of hurricane force winds. Make sure that vulnerable tanks are at least half full at times of vulnerability. Of course it depends on how big the waves are but that strategy should remove most of the risk. So the probability of spill due to tank rupture due to wave action would be a function of the probability of the damaging storm, the probability of the balancing operation not being carried out in a timely fashion, and the probability of even a half full tank being damaged by the damaging storm. I would compare your answer with the literature number for catastrophic tank failure for all tanks in all circumstances, and make sure that your case is more frequent than that value.

HAZOP at

http://www.curryhydrocarbons.ca

 

[unclesyd]

There should be a report on the tanks at Valdez Alaska as they were hit by Tsunami during an earthquake. I think it was the Fairbanks earthquake. I also think the may have been hit another time by a large wave.

The API should have a lot of information on the flooding aspect as there have been quite few incidents where a tank floated and caused a spill. I think they last one was on the Ohio River.

 

[NeilatNEL]

It is feasible to estimate impact forces of different sizes of waves using Computational Fluid Dynamics (CFD) flow modelling methods. This type of approach has been used to look at impact forces on offshore structures and ships (look at the 'green water' movie example at

http://www.math.rug.nl/~veldman/cfd-gallery.html

)

Get in touch if you would like more information on this.

Cheers,

Neil

 

[NeilatNEL]

Sorry,

I should have said, you can reach me at info@nel.uk

Cheers,

Neil

 

[MJCronin]

ab123456,

There is an effort currently to develop new standards for storage tank construction by the American Petroleum Institute (API) to meet seismic considerations, including tidal waves.

Philip Myers, storage tank, specialist with Chevron and author of a very informative book "Aboveground Storage Tank Handbook" is part of this development.

See this link:

http://bulktransporter.com/ar/transportation_new_terminal_storage/

Oregon State University (NEES's Tsunami Wave Basin facility)has also done some research on Tsunami wave impact on Oil Terminal Storage Tank farms. This is in concert with EQE

http://nees.orst.edu/presentations/pres.yim.feb01.PDF

Also, the US Nuclear Regulatory Commision may have information and/or methodologies of stress analysis for the condensate storage tanks that are located at the seaside nuclear power plants.

My opinion only.....

Please let us know about any other source of information you may find


MJC



"People ask my why I do this, and I tell them that I have the heart of a small boy ... and I keep it in a jar on my desk." Stephen King

 

[Hookem]

ab123456: Are these existing tanks founded on ring wall foundations? and bolted to that ringwall? An tank that is empty of all fluids may otherwise "float" in as little as 1.5 to 3 feet of standing static water, much less be pushed around by wave action.