A131 grade A plates API standard 650 open top welded storage tanks

API 620 Crude Oil Tank Non-pressure Parts
Welds for pads, lifting lugs, and other nonpressure parts, as well as temporary lugs for alignment and scaffolding attached to primary components, shall be made in full compliance with a welding procedure qualified in accordance with Q.6.1. Lugs attached for erection purposes shall be removed, and any significant projections of API standard 650 open top welded storage tanks weld metal shall be ground to a smooth contour. Plate that is gouged or torn in removing the lugs shall be repaired using a qualified procedure and then ground to a smooth contour. Where such repairs are made in primary components, the area shall be inspected by the liquid-penetrant method. A visual inspection is adequate for repairs in secondary components.

According to API 650 tanks, anchoring devices should be designed to transfer overturning moments to the API standard 650 open top welded storage tanks tank foundation. At the same time, according to API 650 tank Appendix F, when the tank is to be anchored, the size of the anchoring parts is determined by the maximum lifting force caused by the internal pressure and wind load or the combination of internal pressure and seismic load.

The mechanical seal of floating roof API standard 650 open top welded storage tanks relies on mechanical force to press the sealing steel plate tightly against the tank wall, so that it can slide on the tank wall and avoid gap as far as possible. However, mechanical seal has high requirements for the geometry of storage tank and poor adaptability, so mechanical seal is rarely used in newly built floating roof API standard 650 open top welded storage tanks.