DNV has received a contract from the American Petroleum Institute (API) to execute a program that will provide new insight on large-diameter bolt fatigue, particularly as it relates to subsea systems.
Testing will be performed at DNV’s labs in Columbus, Ohio, and Norway that are equipped to handle capacities of 7500 kN and staffed with experts in fatigue of subsea equipment, bolting connections, cathodic protection, and instrumented tests. It will take place in a controlled environment, recording the number of cycles, stresses, strains, current, pH, and oxygen level.
“The type of fasteners tested are used in critical subsea applications and are often exposed to fatigue loads combined with high pressures and temperatures,” explained Frank Ketelaars, DNV GL - Oil & Gas regional manager, Americas. “Enhanced knowledge of fatigue performance will enable cost-effective designs ensuring safe operations of this critical equipment.”
As the program advances, data from the tests will be made available on DNV’s Veracity open industry platform. This will include key findings and test images as well as logging data, which will allow the API project team to monitor tests and conduct independent analyses.
Testing is slated to be completed by year end.