Tank Inspection Standards and Codes Established for Shop-built Storage Tanks

Storage tanks are the backbone of many industries. Storage tanks offer a safe and reliable option for easy storage and transfer of bulk liquids or gases. Since storage tanks are used for keeping all sorts of things ranging from gases to hazardous materials, the design and construction of storage tanks are stringently regulated. There are several industry standards and codes that regulate how tanks are built and fabricated. Besides this, API tank inspection companies are significantly crucial in ensuring the tanks are in workable condition and pose no explosion or spill threats. Industry leaders develop tank inspection and manufacturing codes and regulations. The codes cover different aspects of tank designing and fabrication, including welding, the thickness of plates, and the design foundation.


Tank manufacturing companies are tasked with designing and fabricating functional and aesthetically appealing tanks and built according to codes and regulations.

Adhering to industry codes allows tank manufacturers to build tanks that are in accordance with federal and state regulations and safeguard the environment.

In this blog, we have discussed some essential codes and standards for shop-built tanks.


API 650 Standard

The American Petroleum Institute has developed API standards and regulations for tank fabricators and manufacturers. API 650 overlooks the construction of welded tanks intended for oils storage. Various aspects of tank fabrication are covered under the API 650 standard, like welding, design, tank assessment, tank installation, and fabrication.

Usually, API 650 tanks are atmospheric tanks. However, API 650 tanks can have internal pressure that should not go over the weight of the covering plates. API 650 tanks are used to store gasoline, gases, chemicals, crude oil, water, etc. The code also requires that the tanks are regularly assessed by professional API 653 tank inspection services providers.


AWWA D100 Standard

AWWA D100 standards govern the manufacturing of welded storage tanks made of steel. These tanks are manufactured for storing water. Different aspects of tank design and fabrication are regulated through the AWWA D100 code. For instance, tank materials, quality assurance, tank foundation, and accessibility of hardware are regulated through this standard.


There are a few variations to the AWWA standard used for different types of water storage tanks.


The AWWA D102 standard is applicable on those steel water tanks that require coating. The AWWA D652 standard is for the disinfection of storage tanks. The water tanks are disinfected soon after being delivered to the facility and installed for usage.


 UL 142 Certification

Atmospheric tanks constructed to store combustible fluids and flammable liquids are required to pass the UL 142 certification. UL 142 code is one amongst the NFPA 30 Flammable and Combustible Liquids Codes. Besides this, the Steel Tank Institute or STI has created the F921 certification for oil and gas storage tanks.


AWWA D100 and API 650 codes are applicable on field-erected and shop-fabricated storage tanks. However, the UL 142 code is only for shop-built tanks. Storage tanks that are UL 142 certified carry a permanent UL Listing Mark.

The UL 142 code requires that the tanks are thoroughly tested for quality assurance and safety.