API 650 welded aluminum storage tanks welding symbols

The API 650 welded aluminum storage 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.

The API 650 is widely used for tanks designed to withstand low internal pressures, for the API 650 welded aluminum storage tanks storage of typical products such as crude oil, petrol, chemicals and water. We have extensive experience when it comes to API 650 tanks, varying from tanks built in the factory up to +/- 500m3, to tanks built on-location up to +/-15,000 m3.

API 650 welded aluminum storage tanks construction must adhere to the design drawings, acceptance specifications and construction plans. If the design needs to be modified during API 650 welded aluminum storage tanks construction, it must be approved by the original design unit or Party A’s representative and relevant personnel of the supervision unit, and written visa procedures must be completed in advance. The equipment and main materials used in the oil tank construction project must have certificates of conformity and quality assurance.