How Do Magnetic Level Indicators Work?

Magnetic Level IndicatorMagnetic Level Indicators also known as MLIs, have revolutionized the global visual indication market by offering a safer, reliable, and high-visibility alternative to common gauge glass assemblies.  They provide high-visibility representation of the liquid level in a vessel. MLIs can be mounted to tanks in a number of different ways. The most popular configuration, however, is called a side-mount.

The Magnetic Level Indicator (MLI) working principle is widely used in many industrial level applications. The operating principle behind a magnetic level indicator is that the MLI shares the same process fluid as the vessel, and therefore shares the same level.

The three primary components to a Magnetic Level Indicator are:
  • The float
  • The chamber
  • The visual indicator

Magnetic Level IndicatorThe float (contained within the chamber) interacts with the externally mounted visual indicator. As liquid rises and falls in the vessel and MLI chamber, the float follows. The magnets in the float interact with magnets inside each indicator flag. As the float rises and falls in the chamber, the magnets slowly turn each flag 180 degrees. This allows the visible flag color to change to a high-contrasting, highly-visible representation of liquid level.



Magnetic Level Indicator



Utilizing a combination of proven buoyancy principles along with the benefits magnetism, MLIs can be customized to fit virtually any process connection arrangement on the vessel.

The chamber and magnetic float is available in a variety of materials and pressure ratings to accommodate the wide variety of complex process applications present in the world’s major industrial facilities.

Areas Where Magnetic Level Indicator Are Applied:

  • Feed water heaters and boilers
  • Refinery and chemical industries
  • Energy and power plant technology
  • Pulp and paper applications
  • Oil and gas industries
  • Gas plants
  • Pipeline compressor applications
  • Pharmaceutical applications
  • Food and beverage applications

For more information about Magnetic Level Indicators (MLI's), contact Miller Energy by calling 800-631-5454 or visit their web site at https://millerenergy.com.

Process Instrumentation and Valves for the Chemical and Petrochemical Industries


Miller Energy provides process control instruments and valves designed to assist in higher quality yields, more efficient processes, and greater plant safety for chemical processing and petrochemical refining manufacturing facilities. 


The Chemical Industry


The chemical industry is key to industrial production. It transforms the raw materials of animals, vegetables and minerals into a host of products used by both the industrial and domestic customers. Lightweight and durable plastic products contribute to fuel effectiveness in transportation, energy-saving insulation material in buildings, paints and protective coatings that extend metal and wood life, soap, shampoo and detergents maintain us clean, pharmaceuticals and disinfectants protect our health. Without vital chemicals, computers and telecommunications systems could not work.

The industry has matured using local resources such as salt, coal, lime, vegetable products and animal fats. It is now a worldwide sector that mainly uses natural gas and oil fractions such as naphtha as the main raw materials. There is a strong awareness of the need to substitute fossil resources both as raw materials and for process energy with sustainable options.

The Petrochemical Manufacturing Industry


The sector produces petrochemicals which are petroleum and natural gas chemicals (organic compounds not burned as fuel). Ethylene, propylene, butylene, benzene, toluene, styrene, xylene, ethyl benzene and cumene are key products. These products are fundamental construction blocks in the manufacturing of consumer products, automotive parts and numerous sustainable and unsustainable goods. These products are fundamental construction blocks in the manufacturing of consumer products, automotive parts and numerous durable goods. This sector does not include organic compounds such as ethyl alcohol and inorganic chemicals such as carbon black.

Olefins and aromatics constitute the building blocks of a large variety of products, including solvents, detergents and adhesives. Polymers and oligomers used in plastics, resins, fibers, elastomers, lubricants and gels are built upon olefins.

Miller Energy: Chemical and Petrochemical Instrumentation and Valve Experts


Miller Energy offers a broad range of instrumentation and valves for these diverse markets. Since 1958, Miller Energy, Inc. has exceeded customers expectations in the Chemical and Petrochemical Industries by specifying and providing the highest quality instrumentation and valves. Known for unparalleled customer service and local technical support, Miller's comprehensive line of pressure, temperature, level, flow and analytical products are available now and ready to solve your most challenging chemical and petrochemical applications.

Contact the Miller Energy office in your area by visiting this web page, or call 800-631-5454 for further assistance.