GENERAL a. This specification covers material@ design@ fabrication@ erection@ and testing requirements for vertical cylindrical aboveground@ closed and open-top@ welded steel storage tanks in various sizes and capacities@ for internal pressures approximating atmospheric pressures. b. This specification is designed to provide the oil industry with tanks of adequate safety and reasonable economy for use in the storage of petroleum and its products and those other liquid products commonly handled and stored by the various branches of the industry. It does not present@ nor is it contemplated to establish@ a fixed series of allowable tank sizes; but rather it is intended to permit the selection by the purchaser of whatever size of tank may be required to best meet his particular needs. This specification is for the convenience of purchasers and manufacturers in ordering@ fabricating@ and erecting tanks and is not intended to prohibit purchasers and manufacturers from purchasing and fabricating tanks meeting specifications other than those contained herein; nor is it intended in any way to prohibit purchasers from purchasing tanks from companies not authorized to use the API monogram. c. Appendix A to this specification presents for ready reference design data relating to tanks which may be built according to specifications contained herein. The data presented in Appendix A are for convenience and are not required in order to comply with this specification. d. Nothing contained in this specification is to be construed as granting any right@ by implication or otherwise@ for manufacture@ sale@ or use in connection with any method@ apparatus@ or product covered by letters patent@ nor as insuring anyone against liability for infringement of letters patent. COMPLIANCE The manufacturer is responsible for complying with all of the provisions of this specification. The purchaser may make any investigation necessary to satisfy himself of compliance by the manufacturer@ and he may reject any material that does not comply with this specification. It is urged that the purchaser avail himself of this right and furnish his own inspection independently of any supervisory inspection furnished by the manufacturer@ and that the purchaser's inspector follow closely all of the details of field construction and testing herein specified@ which affect the integrity and safety of the completed structure.
API STD 650-1961 history
2013API STD 650-2013 Welded Tanks for Oil Storage (Twelfth Edition; Incorporates Errata 1: July 2013@ Addendum 1: September 2014@ Errata 2: December 2014)
2007API STD 650-2007 Welded Tanks for Oil Storage (Eleventh Edition; Incorporating Addendum 1: November 2008; Addendum 2: November 2009; ADDENDUM 3: AUGUST 2011)
1998API STD 650-1998 Welded Steel Tanks for Oil Storage (Tenth Edition; Addendum 1: January 2000; Addendum 2: November 2001; Addendum 3: September 2003; Addendum 4: December 2005)