A841 grade A class 1 plates API Std 650 flat-bottom tanks

API Std 650 flat-bottom tanks belongs to metal oil tank. Metal oil tank is a kind of vessel made by welding steel plate. The common shapes of metal tank are vertical metal tank, horizontal metal tank and spherical metal tank. The advantages of API Std 650 flat-bottom tanks etc. metal oil tank are good sealing, not easy to leak, can be installed with heating and insulation function, metal tank can withstand high internal pressure, large vertical metal tank such as API Std 650 flat-bottom tanks also has the characteristics of small floor space and large storage capacity.

Aftershock Level Earthquake (ALE)
This design case shall be applicable only when regulations or project documents specifically require the tank system to be designed or evaluated for aftershocks.
If the outer tank is not designed as a secondary containment (i.e. it serves as vapor barrier and pressure boundary only and is not constructed of API 620 material suitable for the inner tank API Std 650 flat-bottom tanks), then no design or evaluation for ALE is required by these provisions for the inner or outer tank.

The welded API 650 tank in various sizes and capacities for internal pressures approximating atmospheric pressure (internal pressures not exceeding the weight of the roof plates), but a higher internal pressure API Std 650 flat-bottom tanks is permitted when additional requirements are met.