Storage tank is a common storage unit for manufacturers. In oil industry, storage tank is often found in terminal, refinery and depot for oil storage purposes. It is important for operators to know how much medium is left in the tank. Operators often use measurement of level, temperature, density and pressure to calculate the volume of oil stored in the tank.
Intermediate tank and trade tank are two main types of tanks used in oil industry. Level, temperature and pressure (only from pressurised storage tank) are three main parameters need to be monitored from intermediate tank during operation process. The purpose of monitoring activity is to minimise risks of spillage or over draining from the tank. It is very important to choose the most appropriate and cost-effective instrument for different types and sizes of tank.
Among different types of liquid level transmitter, magnetic flap level meter, submersible level transmitter, radar level meter and differential liquid level transmitter are the most popular types. Magnetic flap level meter has been widely used in oil and petroleum tanks for liquid level measurement compare to others. It is easier to operate with low maintenance requirement compare with others. Below are two main measuring method by using different types of liquid level instrument in oil tank:
- Indirect Measuring Method
With this method liquid level is obtained by converting electric signals detected by sensing element from level meter. For example, differential pressure level transmitter detects the difference of pressure between top and bottom of the tank. Readings are then used to calculate with certain density and temperature compensation to reflect liquid level in the tank.
- Direct Measuring Method
For this method, liquid level is directly measured by installed meter on the tank. This method can help manufacturers to avoid any errors occurred during intermediate conversion. Magnetic flap level meter is one of the main types of measuring instrument can be used with this method. This level meter is considered as a safe and reliable instrument due to its indicator is completely isolated from testing medium. It can also connect to any type of automation control unit such as level switch, valves and alarms to form as an automation control system. Output option allows this unit to communicate to PLC system for central management purposes. This series of side-mounted magnetic tilting column liquid level meter can be widely used in electric power, petroleum, chemical industry, metallurgy, environmental protection, shipbuilding, construction, food and other industries in the production process However, the instrument might suitable to some particularly large viscosity media, such as asphalt.
Inconclusion, there are so many different ways to measuring liquid and solid level from tanks, vessels and containers. To choose the most suitable device according to testing medium is very important to manufacturers. In oil industry, we highly recommend magnetic flap level meter to manufacturers.