RP for Interstitial Tightness Testing of Existing Underground Double Wall Steel Tanks (R012)

The Recommended Practice for Interstitial Tightness Testing of Existing Underground Double Wall Steel Tanks (R012) is applicable to steel tanks built to both the UL 58 “Steel Underground Tanks for Flammable and Combustible Liquids” and UL 1746 “External Corrosion Protection Systems for Steel Underground Storage Tanks” construction.

Topics include:

• Qualifications of Testers
• Code and Testing References
• Explanation of External Pressures
• Interstitial Monitoring Pipe
• Testing Procedures

Proper testing of double wall and secondarily contained underground tanks requires practical experience and careful adherence to recognized good practices and procedures. Because installation of underground storage systems is a specialized craft, it is assumed that persons who use this publication will have a fundamental comprehension of the basics of such procedures as pipefitting, excavating, electrical construction and basic understanding of earth sciences.

Revised: July 2016

Format: PDF