scope:

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

a. Descriptions of the various types of storage tanks.

b. 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 operations.

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.