Magnetic Level Gauges for Visual Tank Level Monitoring and Control

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

indicator.

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.

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