API 650 flat-bottom steel tanks corrosion allowances

Sand blasting and derusting of API 650 flat-bottom steel tanks uses compressed air as power and SiC, pomegranate sand and quartz sand as spraying materials to form high-speed jet beam, which is used to remove rust and dirt on the surface of metal storage tank and improve the binding force of workpiece with coating and plating material. Sand blasting is often used in API 650 flat-bottom steel tanks construction.

The insert plate weld shall not cross any shell seams and shall be at least the greater of 10 times the shell thickness or 12 in. from any other weld in the API 650 flat-bottom steel tanks shell including shell seams, shell-to-bottom weld or attachment welds. The butt weld around the periphery of the plate shall be examined over 100% of its length by both liquid penetrant method and radiographic method. The liquid penetrant examination is required on the root pass, on the back-gouged surface, and on the inside and outside finished weld surfaces. Additionally, the weld shall be vacuum box leak tested.

API 650 petroleum storage tank body design is mainly the design of tank bottom, API 650 flat-bottom steel tanks tank top and tank wall, and the design of tank wall is particularly important. As the main pressure bearing part of API 650 petroleum storage tank, the tank wall bears loads including liquid pressure, wind pressure, seismic load, opening stress, etc. The calculation of such loads is explained in detail in various API 650 flat-bottom steel tanks storage tank design standards. But in addition, the API 650 petroleum storage tank wall also bears the push-pull force and torque of the connected pipeline.