Above Ground Horizontal Cylindrical Tanks

Check pipe standards. Without knowing size and other measurement I have to assume horizontal cylindrical tank comes close to a pipe.

4 mm sounds like an awful lot to small!

More input needed...

• Volume?
• Fluid?
• Temperature?
• Pressure?
• Tank wetted materials?

What does the procurment document say?

Is the tank built to some specification, that you should know???

As PWS says, what are you putting in it? Helium? Water? Propane? Are the ends flat or hemispheres? What kind of support?

These are part of in-service inspections. The diesel tank have flat heads with 2 concrete supports. I've check UL 142 and basing on the dimension and table, the minimum shall be 6.1. Our UT readings are around 4 mm. I thought of calculating the stress on shell but no formulas are written. Anybody who's got a copy of SP-001???

If you have only 4 MM and the original tank specs were 6.1 - what is the corrosion allowance? I would believe that you are below the min wall. You can do an overlay to return the wall thickness if the corrosion is limited to small areas (you can overlay the entire tank however it might be cost prohibited).

If you are below min wall you have to repair or replace!

An inspection role would point out to the Client that the tank is below minimum thickness according to the UL142 document and recommend its phased replacement before it falls off the facility's register for leak indemnity insurance cover. Questions to ask:

• Is it in a secondary containment bund?
• What would be the immediate consequence of its failure?
• What would the clean-up costs, the loss of production costs, the human resource costs and the costs of embarrassment be to the business when it fails, and can those figures be used to justify its early replacement?
• If the costs above cannot justify investment in a replacement tank, then why has it not been decommisioned and divested from the business instead?

The answers would come from the Client's local Operations Management, as might the SP001 document.

Thanks for sharing the information above.

You didn't state the conditions of the material to be stored in the tank. Is this a vented water tank? Is this a compressed gas? Is this a compressed liquid (i.e. - does it have a high vapor pressure? Is the material stored a corrosive? etc. etc.

What is the specific geometry of the tank? Is it a true cylinder, or does the tank have belled ends (round), indicative of a pressure vessel?