A516 Gr 65 plates API standard 650 mechanically-anchored tanks

Tank cracks are common API standard 650 mechanically-anchored tanks defects, mainly including tank wall cracks, internal cracks, weld zone cracks. The reason for these defects may be that the defects not exceeding the standard existed in the early stage of API standard 650 mechanically-anchored tanks construction, which become obvious after the later use. Or in the process of using the API standard 650 mechanically-anchored tanks, the tank body material generated new defects due to corrosion, pressure, wear and other reasons, and tank cracks.

In this project a cylindrical tank 75 ft in diameter is designed for an internal pressure of 0.5 lbf/in.2 gauge in the vapor space. The plate material is ASTM A131 Grade B steel for thicknesses of 1/2 in. and less.
The top course of the butt-welded cylindrical sidewall is 1/4 in. thick. The tank API standard 650 mechanically-anchored tanks roof is a conical shape with a 2:12 slope and a 1/4 in. thickness with single full-fillet welded lap joints. The maximum design liquid level is 6 in. below the plane of juncture of the roof and sidewall.

Standard API 650 tank calls for calculations based on the specific gravity of the liquid product being stored. This permits the thickness of the steel API standard 650 mechanically-anchored tanks needed as well as other specifications of how the tank is built to be determined by the weight of the API 650 tank.