API 650 Design Criteria for a 10'x8' Access Hatch

[copelajo]

Can someone direct me to the API 650 design criteria for a 10'x8' hatch? The largest opening detailed in section 5.7 is 48"x48". A customer is looking for a reusable cleaning access, but I have never come across something of this size. Any help would be greatly appreciated.

 

[bimr]

How often is your client planning to use the "hatch"?

Usually when these tanks are repaired, the section is cut out for access and then replaced when the work is complete.

 

[copelajo]

The scope of work calls for exactly the operation you mentioned, but they requested cost for the option of "installing a removable door panel for future cleaning of the tank." We have removed and replaced sections many time before, but I have never made an access panel to be reused.

 

[JStephen]

There's not any API-650 design criteria for such a hatch; it does not meet the API-650 standard.

They probably need to invest their money in smaller equipment rather than bigger hatches.

 

[copelajo]

That's what I thought, but I want to make sure I didn't miss something.

Thank you for the informative and quick responses!

 

[JStephen]

I will point out also, that this has been done, just not per API-650. See the linked article:

http://www.msha.gov/fatals/metal/2014/final-reports/final-m14-21.pdf

 

[McEng29]

What is your clients purpose for such a large cleanout? A 48" x 48" cleanout should be more than enough, and as stated before, anything larger than that does not meet API 650 std, section 5.7.7.1.

 

[copelajo]

The primary purpose is to accommodate excavators and other equipment involved in the removal of the concrete floor. Other work such a drive replacement and rake servicing will make use of the access.