3 replies to this topic

[icasensio]

Number of drain connections in atmospheric tanks

Dear all,

I have a question about the topic: How many drain connections should I have to consider in an atmospheric tank?

I always had considered only one, but a colleague has asked me about it. This tank will contain crude and naphtha so I have looked for in API 650 but I have found nothing, except the figure and size of sump.

Anyone knows some rule or standard that recommends the number of drain connections?

If more information is needed, please, let me know.

Regards.

[Art Montemayor]

Inés:

There are no “rules”, “standards”, “codes”, or legislation available regarding the number of drains to be installed on an atmospheric storage tank. There is no one that is going to make that decision for you if you are empowered as the process design engineer on this tank installation. That is what engineers are supposed to do: make critical and specific decisions regarding the design of equipment they are responsible for. That is why we are hired and what is expected of us. If you make the right decision and the right design, you and your career come out ahead. If you fail with the wrong decision and apply a bad design, you pay the consequences.

No one on this Forum is capable of telling you (or recommending) the quantity (and sizes) of drain nozzles required by your tank and its application. We don’t know anything about the Scope of Work and the Design Basis with regards to this tank. You obviously do know that information (or can obtain it), so YOU are the best judge and jury to make that decision. That is normal, everyday process design engineering.

Sorry that we can’t help you make that decision – or the sizes of the nozzles – but if all we needed to do was refer to “rules”, “standards”, and cook book recipes with the correct results, then our employers wouldn’t need graduate engineers to make those decisions and judgments. Anyone could do it, as long as they could read and follow the instructions.

[himant]

Well said!

Acc. to me, only one drain will suffice the purpose. Moreover, I have never seen any tank with two drains!

[kkala]

Some notes in addition to previous posts:
For a tank with cone-up bottom, drains should be as many as the sumps.
For a tank with cone-down bottom, there is one drain from the bottom center.
For some examples and for more details on bottoms and sumps, go to http://www.cheresour...-or-down-design '> http://www.cheresour...-or-down-design .