1.1 This guide is intended to provide the reader with a knowledge of construction examination procedures and current technologies that can be used to give an owner or operator of an aboveground storage tank (AST) in petroleum service, relevant information on the hydraulic integrity of a new, repaired, or reconstructed tank bottom prior to return to service. This guide does not pertain to horizontal ASTs, manufacture of tanks using UL 142, or to tanks constructed of concrete or other non-ferrous materials.

1.2 The adoption of the methods and technologies presented in this guide are not mandatory, rather they represent options that may be selected to identify the likelihood of product leaking through a new, repaired, or reconstructed tank bottom.

1.3 This guide is not intended to suggest or treat any technology in a preferential manner.

1.4 The person responsible for applying this guide should be a knowledgeable individual with experience in the design, inspection, construction, or combination thereof, of aboveground storage tanks for use in petroleum service, and should also be certified under the requirements of API 653 when use is related to tank bottom repair.

1.5 Refer to API RP 575 for useful information and recommended practices for maintenance and inspection of atmospheric and low pressure stirage tanks.

1.6 This guide is written in metric measure units (SI