InConsider a steel tank like a plastic water bucket. When we pour water into the bucket the plastic walls tend to expand then again come back.After we have filled the bucket fully, we see that the top rim of the bucket tends not to be perfectly circular, but a bit elliptical in shape.When we stir our hand inside water we see that the bucket walls tend to warp What has been mentioned above is exactly what happens to a large steel tank of oil or chemical.As it is daily filled in and out with oil, there tends to be deformation of the tank walls, pressure on the tank floorand specially if it is a floating roof tank, the roof rim tends to go out of shape which can hinder movement of the floating roof due to uneven foam seal gap.Also due to enormous weight of liquid pressure exerted on the tank bottom, the tank bottom tends to subside which can causecracks in joints and make the tank tilted on one side gradually affecting centre of gravity..
The tank can also tilt to one side due to uneven liquid head pressure. All this phenomenon is called out of roundness, tank tilt and tank floor settlement. If these are not studied and a detailed report made where you can repair,you can understand the catastrophe and safety/technical issues involved.It is this tank health that needs to be studied under API 653 B standard. To measure, study, analyze and make proper reports is very difficult.We have tonnes of experience in the field of tank calibration all over the world for 22 years which has given us invaluable experience to study tank health with our accurate total stations, laser basedequipments and experienced engineers. After a few years of use, large tanks should always be studied for tank roundness, tilt and bottom settlement.We have mastered this art of tank health checkup which can also include a detailed ultrasonic thickness report of tank floor and shells as floors can corrode over time, especially MS tanks.So when tanks are decommissioned for any repair or cleaning, they should be studied as mentioned above. Just give us a call oe mail us.Tanks are your asset and oil is your lifeline.We are available to do this study around the globe. All it takes is to contact us. I have included a report of what can be in roundness, tilt and settlement survey.