Above ground storage tanks require intensive maintenance to keep them in the best condition while being in line with regulatory standards. Such tanks are made of metal, and they hold many types of liquid and gas substances, from water to chemicals.
The guidelines for inspecting these metal tanks from the tank foundation to its shell is developed by the American Petroleum Institute (API). Particularly with API 653, inspection service protocols, among others, are laid out for proper guidance. So before having your tank inspected, be aware of some considerations, advises Heartland Tank Services.
An inspector should be certified by API through its Individual Certification Programs (ICP). After passing the test, inspectors receive an individual inspector number. They also have to take tests every three years. Apart from an API certification, inspectors must have at least four years of experience in working with storage tanks.
Standard Inspection Protocol
An inspector must follow the standards when inspecting storage tanks. They must:
visually inspect the welds, the plates, and the appurtenances;
test shell courses, the floor, and the roof using UT (ultra-sonic thickness) test;
vacuum test the floor weld seams;
check for any side corrosion in the tank’s floors;
do a settlement survey (i.e. check for planar tilt, floor bulges, floor depressions); and
compute for safe fill height.
Regular inspections of storage tanks are imperative. They not only prolong the life of the tank but also:
prevent liquid to leak into an existing secondary containment and even into groundwater;
create a threshold of the condition of the tank as well as its corrosion rates;
determine issues before a repair is made or before a leak occurs;
protect the value of your asset; and
reduce the probability of costly tank failure.
The potential impact of tank leaks and failures is immense. That’s why maintaining your storage tank is mandatory. You need qualified inspectors who strictly follow an industry-regulated protocol.