Magnetic Level Indication
What is a magnetic level indicator (MLI)?
A magnetic level indicator is an externally mounted chamber with visual indicators that are completely isolated from the process liquid. Inside the chamber is a magnetic float that rises and falls with the level of the liquid. When the float moves, it causes flags inside the chamber to turn and mark the level on an exterior indicator numbered roughly like a meter stick. Magnetic gauges are often used in conjunction with through-air or guided wave radar as a redundant level measurement.
Magnetic level transmitters were initially introduced as alternatives to sight glasses. Over time, glasses become compromised through leaking seals, clouding, and breakage; MLI technology is not susceptible to these weaknesses.
What are the advantages of using a magnetic level transmitter?
The chief benefit of using an MLI is isolation from process liquid. Separation allows for easy access to the level gauge for cleaning and eliminates contact with difficult media. Magnetic level indicators are commonly low-cost in comparison with other level technologies, and can provide visual indication of level from a distance. In fact, VEGA magnetic gauges make level visible from up to 200 feet away.
What are common applications for magnetic level indicators?
Application examples for magnetic level indicators
In the preflash drum, the medium is heated before it is fed into the distillation column. Accurate and reliable level control is a critical factor in ensuring efficient operation of the distillation column. Reliable measurement of the level prevents overfilling of the vessel and also keeps the pumps from running dry.
Reliable and redundant measurement even under extreme process conditions
Level measurement in propane bullets
Propane, a flammable, colourless and odourless gas, is one of the many types of liquefied petroleum gases (LPG) that exist. It is produced from natural gas via a special refining process. Propane is compressed, liquefied and stored in pressure vessels so that it does not return to a gaseous state. To ensure optimal storage, reliable level measurement is required.
Redundant measurement increases plant availability and plant safety
Easy installation and setup
Level and interface measurement and point level detection in separators
Exact interface measurement in separators is important for ensuring the quality of the separation process. Continuous control of the interface between oil and water ensures that oil is not inadvertently withdrawn instead of water. This saves costs and increases the efficiency of the plant. A vibrating level switch serves as an additional overfill protection mechanism.
Redundant measurement for highest safety standards
Sour water stripper
Interface measurement in the sour water stripper
Safe and reliable measurement of the separation layers in the sour water stripper is extremely important in preventing sour water from accidentally getting into other parts of the plant. Sour water is highly corrosive and can cause serious damage over time, leading to safety problems in other process vessels and pipes. The sour water discharged from the stripper is delivered to the desulphurisation plant for further processing.
Redundant level monitoring
Low maintenance costs
Easy mounting on standard tanks