66m diameter API 650 mechanically-anchored flat-bottom tanks

The API 650 mechanically-anchored flat-bottom tanks stiffener ring and backing strip (if used) are primary components, and they shall comply with the requirements of API 620 storage steel tank Q.2.1. The stiffener rings may be fabricated from plate using an intermittent weld on alternating sides between the web and the flange.
Except for aluminum or stainless steel tanks, all fillet welds shall consist of a minimum of two passes. The ends of the fillet welds shall be 2 in. from the rat hole (see Figure Q-1), and these welds shall be deposited by starting 2 in. from the rat hole and welding away from the rat hole. An acceptable alternative to the detail that includes stopping fillet welds 2 in. short of the rat hole would be to weld continuously through the rat hole from one side of the stiffener to the opposite side. All craters in fillet welds shall be repaired by back welding.

Tanks which are designed following rules and guidelines of API 650 are API 650 tanks. API 650 API 650 mechanically-anchored flat-bottom tanks is the governing code for Welded tanks for Oil storage normally operating in the atmospheric pressure range. The code API 650 provides guidelines for design, fabrication, material, erection, and inspection of welded vertical and cylindrical storage tanks. Such API 650 mechanically-anchored flat-bottom tanks Tanks must be above ground with a closed or open top.

The safety inspection of atmospheric storage tank, API 650 mechanically-anchored flat-bottom 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 mechanically-anchored flat-bottom 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.