Inspection requirements for API standard 650 unanchored flat-bottom tank

The API standard 650 unanchored flat-bottom tank stiffener ring and backing strip (if used) are primary components, and they shall comply with the requirements of API 620 storage steel tank Q.2.1. The stiffener rings may be fabricated from plate using an intermittent weld on alternating sides between the web and the flange.
Except for aluminum or stainless steel tanks, all fillet welds shall consist of a minimum of two passes. The ends of the fillet welds shall be 2 in. from the rat hole (see Figure Q-1), and these welds shall be deposited by starting 2 in. from the rat hole and welding away from the rat hole. An acceptable alternative to the detail that includes stopping fillet welds 2 in. short of the rat hole would be to weld continuously through the rat hole from one side of the stiffener to the opposite side. All craters in fillet welds shall be repaired by back welding.

In API 650 oil storage tank, when the mixing ratio of combustible medium and air reaches a certain limit, it is easy to cause explosion. Therefore, it is necessary to add API standard 650 unanchored flat-bottom tank external floating roof to open cylindrical steel API standard 650 unanchored flat-bottom tank tank. At present, the external floating roof is most suitable for large-scale API 650 oil storage tank in China, ranging from 20000, 30000, 50000 cubic meters to 100000 cubic meters.

1200 tons API 5LGRB strips to Bangladesh. In December of 2015, we get one tender project from National Tubes Limited, which is a famous national enterprise in Bangladesh. It is an order of 1200 tons API 5L Gr. B steel strips, they bought these cargo to fabricate ERW pipe in local place.

Usually, the soil resistance of the foundation should be considered before the design and construction of API standard 650 unanchored flat-bottom tank. The soil endurance in the API standard 650 unanchored flat-bottom tank construction area plays a decisive role in the basic cost of the tank. In areas with high soil resistance, not only the cost of foundation treatment can be greatly reduced, but also the ratio of height to diameter of storage tank can be obtained. Therefore, the investment cost of the API standard 650 unanchored flat-bottom tank can be greatly saved in the area with large soil resistance.

Both parties shall confirm the API standard 650 unanchored flat-bottom tank material object and the quality of the products, confirm the reasons for the defects and the quality of the products, and sign the quality inspection agreement. Major quality objections shall be reported to relevant leaders in a timely manner, and shall be discussed and solved with the API standard 650 unanchored flat-bottom tank steel plant.