Repad Sizing for Rectangular Opening in Tank 1

[merton]

I have a situation where a 24" x 36" rectangular manway has been specified in a 1500 BBL (21'-6" diameter x 24'-0 high) storage tank.

How do I determine the proper size of reinforcing pad for this opening? API 650 forcuses mainly on round shell openings.

Thank you

 

[IFRs]

Same principle. Replace the vertical area removed. Pay special attention to the square corners of the opening - can they be rounded somehow?

 

[JStephen]

Refer to the reinforcing rules of API-650. (Not the table, the text paragraphs that discuss reinforcing).

Note particularly that you can figure the required reinforcing area as the "required" thickness times the whole size. And plate thickness above the "required" thickness can be counted toward that reinforcing. This means on most small tanks, the nozzles are inherently self-reinforced.

Check that the floor plate under the opening furnishes reinforcing equal to half the total required, as well.

I assume this is an API 12D (or is it F?) tank- in that case, I'd use API-650, App. A, with 70% joint efficiency to calculate shell thickness.

 

[JoeTank]

I recall that one of the API 12 series specs have standard details for rectangular clean out doors. That might be a useful reference.

Steve Braune
Tank Industry Consultants

http://www.tankindustry.com

 

[JoeTank]

Just a reminder... you will not be able to certify that the tank conforms to API-650 if you use square cornered openings.

Steve Braune
Tank Industry Consultants

http://www.tankindustry.com

 

[JStephen]

Steve, I've got the field-erected one downloaded. They show the door dimensions, but state that the manufacturer is to design the reinforcing, if required. No details on the reinforcing, either.

And that should be "hole" up there, not "whole".