scope:

This document provides useful information and recommended practices for the maintenance and inspection of atmospheric and low-pressure storage tanks. While these maintenance and inspection guidelines may apply to other types of tanks, these practices are intended primarily for existing tanks that were constructed to one of the following four standards: API Std 12A, API Spec 12C, API Std 620, or API Std 650.This document addresses the following:

a) descriptions and illustrations of the various types of storage tanks;

b) new tank construction standards;

c) maintenance practices;

d) reasons for inspection;

e) causes of deterioration;

f) frequency of inspection;

g) methods of inspection;

h) inspection of repairs;

i) preparation of records and reports;

j) safe and efficient operation;

k) leak prevention methods.

This recommended practice is intended to supplement API Std 653, which provides minimum requirements for maintaining the integrity of storage tanks after they have been placed in service.