Frangible roof API standard 650 ambient temperature tanks

For floating roof API 650 tanks, the net working capacity is the liquid volume contained between the API standard 650 ambient temperature tanks maximum operating level (300 mm below rim for metallic type seals and 600 mm below rim for fabric type seals) and the minimum operating level (API 650 tanks roof supports clearing the tank bottom by 25 mm while set at the operating position).

Large-scale vertical API standard 650 ambient temperature tanks mostly use internal tank bottom heating coils to heat the medium stored in the storage tanks. The heating coils are mostly smooth tube structures arranged in an annular circle along the bottom of the API standard 650 ambient temperature tanks. Commonly used heating methods include hot oil circulation heating method and hot water steam circulation heating method. The hot oil circulation heating method is to continuously extract part of the liquid medium from the storage tank, and then return it to the container to mix with the medium in the tank after heating, and the heat is quickly transferred through mechanical stirring.

In this project, an elemental area of tank wall used is constructed of ASTM A442 Grade 55 steel plate subjected to a meridional unit force, T1, of 4000 lbf/in.2 tension and a latitudinal unit force, T2, of 5060 lbf/in.2 compression. The meridional radius of curvature, R1, is 75 in., and the length of the normal from the surface to the axis of revolution, R2, is 300 in. The joints in the wall are of double-welded butt-joint construction with a tensile efficiency of 85%. A corrosion allowance of 1/16 in. is required.
The problem in this example is to graphically find the minimum thickness of tank wall required for the given conditions (see 5.10.3.3).
Solution: As determined from Table 5-1, the maximum allowable tensile stress value, Sts, for ASTM A442 Grade 55 steel plate in simple tension is 16,500 lbf/in.2. Since the compressive stress is latitudinal, the governing value of R in this situation is R1, or 75 in.

Our quality control department will do inspection for details of the steel materials API standard 650 ambient temperature tanks before delivery. We would invite the customer side to attend the inspection together. If they can not come, we will also take rich pictures for them to check. Meanwhile, we will publish inspection report and send them the PDF version. Besides, we accept any third party inspection such as SGS, BV, etc. And our quality control department will support the third party to inspect the steel materials smoothly and try our best to deliver the qualified steel materials to customers earlier.

In view of the characteristics of container transportation, such as high added value, low cargo damage and short time, our company takes more consideration of port collection and distribution conditions, port facilities, flight density and route coverage when choosing ports. For the convenience of customers, as well as the safety of goods.