A841 grade B plates API Std 650 partially anchored liquid-storage tanks

Requirements for prefabrication of bottom plate of large vertical API Std 650 partially anchored liquid-storage tanks:
1. The diameter of tank bottom should be enlarged by 0.1% ~ 0.15% according to the design diameter.
2. The minimum dimension of edge plate along the radius direction of tank bottom shall not be less than 700mm.
3. The distance between any adjacent welds of the base plate shall not be less than 300 mm.

Charpy V-notch specimens shall be taken from the weld metal and from the heat-affected zone of the welding procedure qualification test plates or from duplicate test plates.
Weld metal impact specimens shall be taken across the weld with the notch in the API 620 oil tank material weld metal. The specimen shall be oriented so that the notch is normal to the surface of the material. One face of the specimen shall be substantially parallel to and within 1/16 in. of the surface.

API standard 650, Welded Tanks for Oil Storage, Thirteenth Edition, has been published to ensure the safety, sustainability, and environmental performance of API Std 650 partially anchored liquid-storage tanks oil storage tanks. The updated standard will help continue operational excellence and trust between operators and manufacturers.