API 650 mechanically-anchored steel tanks inspecting requirements

Suggested Practice Regarding Installation of Low-pressure storage tanks
Access: All openings and accessories for tanks API 650 mechanically-anchored steel tanks constructed according to this standard shall be installed so that any periodic inspections required can be readily made.
Corrosion: When a tank bottom rests directly on the ground, a survey shall be made to establish the need for cathodic protection.
Drainage: All tanks in which water might accumulate under the hydrocarbon contents shall be provided with adequate drains that are suitably protected from freezing.

Prevent the storage liquid from impacting the inner wall of the API 650 petroleum storage tank or increase the internal pressure, reduce the corrosion of the tank top and the tank wall, and extend the service life of the API 650 mechanically-anchored steel tanks storage tank.

Natural ventilation loss: the main cause of natural ventilation loss is that the API 650 mechanically-anchored steel tanks is not tightly sealed. This is usually due to corrosion perforation on the top of the oil tank, or there is a height difference between the two orifices. The air tightness of the mixture in the API 650 mechanically-anchored steel tanks is higher than that of the air, which causes the mixture gas in the tank to be discharged into the atmosphere from the lower hole, and the external air flows into the tank from the high hole, resulting in natural ventilation loss.