API 650 anchored tanks seismic design factors

The safety inspection of atmospheric storage tank, API 650 anchored tanks is divided into external inspection, internal and external inspection and comprehensive inspection. External inspection shall be conducted at least once a year, internal and external inspection shall be conducted at least once every three years, and comprehensive inspection shall be conducted at least once every six years. The safety inspection of large atmospheric storage tanks, API 650 anchored tanks requires special attention: the parts where the liquid level often fluctuates, the parts that are susceptible to corrosion, and the parts that are deformed and worn during use should be checked.

The tank shall be filled with water to the design liquid level unless height is limited as noted in API 620 standard Q.8.1. After the tank is filled with water and before the pneumatic pressure is applied, anchorage, if provided, shall be tightened against the hold-down brackets. All welds in the API 650 anchored tanks shell, including the corner weld between the shell and the bottom, shall be visually checked for tightness.

API 650 can store oil, gas, chemical, water and biofuel for some of the most common tanks in the oil industry. API 650 can store contents at a lower pressure (maximum of 2 PSI) but at much higher temperature (-40 degrees F to 500 degrees F) than the standards of API 650 anchored tanks. It can be any tank size.