Magnetic Level Gauges for Visual Tank Level Monitoring and Control

Magnetic Level Gauges
Magnetic Level Gauges
(courtesy of Hawk Measurement)
Magnetic Level Gauges (MLG) are widely applied in the monitoring and process control of liquid level and interface for many industries; such as petroleum, chemical, power, paper, metallurgy, water treatment etc. They are suitable for real time, precise, safe and reliable continuous measurement of process level.

Based on the principle of magnetic coupling and buoyancy, the magnetic level gauge provides real-time measurement for level and interface. The Magnetic Level Gauge (MLG) is connected to a process vessel. Within the chamber is a float containing a 360° magnetic ring. Outside of the chamber is an indicator equipped with a vacuum glass tube, which contains a bi-colored two-face magnetic bargraph. In response to the level movement, the float moves accordingly, forcing the magnetic bargraph to turn and change color. True liquid level is indicated or “read” from the corresponding point on the measuring scale. The indicator uses hermetical sealed glass tube technology to clearly indicate the level, which eliminates the common problems of glass gauges, such as vapor, condensation and liquid leakage etc.

Typical Applications:
  • Boiler: Steam drum liquid level
  • Power generation: Auxiliary machinery liquid level (HP reheater, LP reheater, deaerator, condenser and heating network heater etc), chemical water
  • Coal Chemical: Methanol, dimethyl ether, synthesis ammonia/urea, MTO, CTL, SNG
  • Silicon industry: Organic silicon, polycrystalline silicon
  • Petroleum and petrochemical: Oil and gas, ethylene, trimerization and etc.
  • Fine Chemicals: Methane oxide, epoxy ethane, aniline, PTMEG, BDO, carbon fiber, POM,acetic acid, styrene, rubber, crude benzol refining
  • Others: Metallurgy, paper-making, water treatment, biological, pharmaceutical, food and beverage etc.
Magnetic Level Gauges have a simple modular design, composed a main chamber, a float and an
mag level gauge construction
Mag level gauge construction

Typical main chamber features:

  • ANSI standard design or special manufacture
  • Multi-forms installation and process connection
  • Chamber Material: 304/304LSS, 316/316LSS, 317SS, 321SS, 347SS, Ti2, Hastelloy C-276, Zr-702, Nickel-6, 304+PTFE, CPVC and PP.

Typical float features:

The float is the key component of the level gauge, which magnetically couples to the outside indicator, liquid level switch and transmitter.

  • Hermetically sealed incompressible
  • 360° magnetic ring
  • 316LSS, Hastelloy C-276, Zr-702, Nickel 6, Ti2, 304SS+PFA, grade V aviation titanium alloy and other materials
  • Special structure and precision manufacturing technology of pulse TIG and laser weld
  • Range of temperature: -320 to 1000°F (-196 to 538°C)
  • Range of pressure: vacuum to 600 psig (vacuum to 42MPa)
  • Suitable for harsh working conditions, such as HTHP, cryogenics and strong corrosion.
mag level float
Relationship of float, chamber and indicator.
Typical indicator features:
  • 316SS or aluminium ruler
  • Hermetically sealed glass tube with no contact with medium
  • Magnetic bargraph is made from special high and low temperature - resistant materials
  • Magnetic bargraph is mechanically interlocked to avoid random rotating
  • Selectable engineering units
  • Immune to oxidation, corrosion and the effects of dust