【国外标准】 Standard Guide for Three Methods of Assessing Buried Steel Tanks

4.1 This guide provides three methods for determining the suitability of a buried steel tank to be upgraded with cathodic protection.4.2 This guide may be used to assess any UST, including non-regulated USTs.4.3 This guide provides three alternative methods but does not recommend any specific method or application. The responsibility for selection of a method rests with the user.4.4 This guide has specific suggestions for vendor provided information which should be requested and reviewed by the user.1.1 This guide covers procedures to be implemented prior to the application of cathodic protection for evaluating the suitability of a tank for upgrading by cathodic protection alone.1.2 Three procedures are described and identified as Methods A, B, and C.1.2.1 Method A—Noninvasive with primary emphasis on statistical and electrochemical analysis of external site environment corrosion data.1.2.2 Method B—Invasive ultrasonic thickness testing with external corrosion evaluation.1.2.3 Method C—Invasive permanently recorded visual inspection and evaluation including external corrosion assessment.1.3 This guide presents the methodology and the procedures utilizing site and tank specific data for determining a tank’s condition and the suitability for such tanks to be upgraded with cathodic protection.1.4 While this guide provides minimum procedures for assessing a tank's condition, this guide does not provide minimum installation procedures or requirements for upgrades of the tank by cathodic protection.1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.