API 650 self-anchored tanks liquid penetrant examination

Temporary Openings after Hydrostatic Test
When approved by the Purchaser in writing, and only in the case of tanks which when complete have no shell penetrations, it is permitted to restore by welding up to four temporary shell openings after the hydrostatic test in accordance with the provisions of this section. Each temporary opening shall be restored by the insertion of a shell plate that matches the thickness and specification of adjacent shell material, and is welded into place with full fusion butt-welds. The API 650 self-anchored tanks insert plate shall be round with diameter no less than 24 in. and no greater than 42 in.

The outer layer of API 650 tank is glass fiber reinforced plastic layer with a thickness of more than 2.5mm, which API 650 self-anchored tanks has strong corrosion resistance and electric corrosion resistance. Special process technology is used between the two layers to make the gap reach 0.1 mm, so as to eliminate the existence of potential safety hazard from the root.

After using for a certain period of time, it is necessary to check the corrosion protection of the metal oil tank and paint the outer wall of the API 650 self-anchored tanks with anti-corrosion paint. The inlet and outlet valves of API 650 self-anchored tanks shall be inspected and maintained regularly to ensure they are in good condition. Oil tank will produce a lot of dirt when it is stored for a long time. Usually, the cleaning cycle of metal oil tank is about three to five years.