API-650 Welded Tanks for Oil Storage

API-650 - 12TH EDITION - CURRENT -- See the following: API-650/ADD 2
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Included in this current edition are the following subparts:

 12TH EDITION - March 1, 2013
 12TH EDITION ADDENDUM 1 - Sept. 1, 2014
 12TH EDITION ADDENDUM 2 - Jan. 1, 2016
 12TH EDITION ADDENDUM 3 - Aug. 1, 2018


This standard establishes minimum requirements for material, design, fabrication, erection, and inspection for vertical, cylindrical, aboveground, closed- and open-top, welded storage tanks in various sizes and capacities for internal pressures approximating atmospheric pressure (internal pressures not exceeding the weight of the roof plates), but a higher internal pressure is permitted when additional requirements are met. This standard applies only to tanks whose entire bottom is uniformly supported and to tanks in non-refrigerated service that have a maximum design temperature of 93 °C (200 °F) or less.

This standard is designed to provide industry with tanks of adequate safety and reasonable economy for use in the storage of petroleum, petroleum products, and other liquid products. This standard does not present or establish a fixed series of allowable tank sizes; instead, it is intended to permit the Purchaser to select whatever size tank may best meet his needs. This standard is intended to help Purchasers and Manufacturers in ordering, fabricating, and erecting tanks; it is not intended to prohibit Purchasers and Manufacturers from purchasing or fabricating tanks that meet specifications other than those contained in this standard.


Claudia's Notes:
This Standard is based on the accumulated knowledge and experience of Purchasers and Manufacturers of welded oil storage tanks of various sizes and capacities for internal pressures not more than 17.2 kPa (21/2 pounds per square inch) gauge. This Standard is meant to be a purchase specification to facilitate the manufacture and procurement of storage tanks for the petroleum industry.

The design rules given in this Standard are minimum requirements. More stringent design rules specified by the Purchaser or furnished by the Manufacturer are acceptable when mutually agreed upon by the Purchaser and the Manufacturer. This Standard is not to be interpreted as approving, recommending, or endorsing any specific design or as limiting the method of design or construction.

There are 26 Appendices provide a number of design options requiring decisions by the Purchaser, standard requirements, recommendations, and information that supplements the basic standard.

Changes from the previous API 650 11th Edition are noted by the use of black lines in the margins.

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Publication Date

March 1, 2013

Page Count

514 pages