API 650 welded tanks for oil storage greater than 60 m (200 ft) in diameter

The API 650 specification provides guidelines for the API 650 welded tanks for oil storage design, manufacturing, materials, installation and inspection of welded vertical and cylindrical tanks. Such containers must be on the ground and have a closed or open top.

Our after sales department is an very important part of our department structures. After the customer receive steel materials, our after sales department will follow up regularly and solve problems for them in time if they have the needs. We romise to return the goods for free for its lifetime if it is quality of the steel material itself. Meanwhile, if you have any advice or complaints, also welcome to feed back to our after sales department, and we are trying to give better service to you.

We should help solve the customer's problems in time, not just verbally, without solving the problems or shirking the responsibility. Improving after-sales efficiency can make customers feel respect. We should take their problems seriously and show sincerity. It can also give customers a good impression and reduce the negative impact.

Investigation of Subgrade
On actual steel storage tank sites to be used, test borings or test pits, or both, may be made at the direction of a competent engineer who will specify the number and location. They need not be equally spaced but should be laid out to uncover possible weak spots.
In general, test loadings of subgrade at the bottom of test pits need be resorted to only when such heavy loading as may be imposed by footings for major column supports for spheres or similarly elevated API 620 low-pressure tanks is specified. Results may be deceptive if average load-bearing capacity over a considerable area is wanted. All field data shall be recorded with maps, and copies shall be supplied to all engineers concerned with design, erection, and later operation.