Magnetic level gauge-FAQ

A magnetic level gauge is a device that measures the level of fluid in the system. It has a floatable device that tends to float in high and low-density fluids with a simple, reliable, and effective way to measure fluid inside the tank.

This guide aims to provide the readers with all the essential information about magnetic level gauges. You will surely understand the functions, specifications, applications, and magnetic level gauge working operation at the end of the guide.

1. What is a magnetic level gauge?

The magnetic level gauge consists of an indicator with a permanent magnet inside the float. The rise and fall of the indicator show the level of fluid inside the vessel. The magnetic level gauge can measure the intense environmental conditions up to 210 bars at 370°C.

The magnetic level gauge has a simple, reliable, and safer application. It has various materials and pressure ratings to fit them with a wide variety of industrial applications. In addition, the level controller body and floats are made of PVC to provide acid resistance and anti-corrosion properties.

2. How does a magnetic level gauge works?

The magnetic level gauge works by using magnetism that links the indicator to the float. It results in providing an accurate level of fluid. The indicator moves in response to changes in float. The level of fluid in the vessel is the same as the level in the measuring chamber. The magnetic level gauge works on conductivity and consists of three main components, the float, the chamber, and the indicator.

The main component of the gauge is the chamber that has been constructed with non-magnetic material. It is mounted to the vessel’s side, where the liquid level in the chamber matches the liquid level in the vessel. The magnetic level gauge can handle highly corrosive material and other extreme applications.

3. What are the components of a magnetic level gauge?

The magnetic level gauge measures the level of fluid. The three components consist of the chamber, the float, and the indicator. The magnetic level gauge uses a float to get a reading. The float has a set of permanent magnets and has the material of 316 stainless steel or titanium. There are options of other materials where needed.

The float has the purpose of projecting the magnetic field through the chamber. It mounts the indicator system inside the vessel to view internal fluid levels and has rotating flags with bright colors to make them visible. There is a magnetic assembly attached with each flag to identify any false indication due to vibration. The magnetic level gauge uses a buoyancy principle with the reliability of magnets that ensures that your readings are accurate.

4. What are the specifications of the magnetic level gauge?

The most common material of magnetic level gauges is 304 stainless steel or 304L stainless steel. However, it could be of alloy or other material for specific applications. The magnetic level gauge has a maximum pressure range of up to 250 bars and the temperature range of 450°C. The float drain length has a density of 590kg/m³, depending on the pressure and temperature.

The float chamber wall thickness for extreme pressure and temperature should be 80 or 160 and must meet ASME/ANSI code. There should be o-type fittings in the branch connections as per the ASME code. There are springs attached to the top and bottom of the chamber to protect the float from damage. The aluminum surface of the magnetic level gauge has a minimum of 20 microns anodic coating for UV protection.

Guided and pressurized floats are not suitable for magnetic level gauges. Instead, the indicators should have a double O-Ring sealed and protected in the aluminum housing. Floats are magnetized and re-magnetized after assembling.

5. Does the magnetic level gauge provide accurate readings?

The material of the magnetic level gauge is stainless steel, making it a highly reliable, durable, and anti-corrosive instrument. This gauge is designed to make it applicable in complex applications where other instruments may fail. In addition, the magnetic level gauge provides accurate readings and can hold in extreme and highly corrosive environments.

The magnetic level gauge can also withstand high pressure and temperature, hazardous material, vibrations, and system shocks. The use of magnetism in these gauges ensures that the measurements are not affected even if you lose power. This feature helps to keep track of fluid levels.

6. What are the considerations for using a magnetic level gauge?

The magnetic level gauge is a valuable and reliable measuring tool. Because of its operation based on a magnetism shuttle that moves in conjunction with float’s magnets, there is no need for restrictive mechanical guide rails. Instead, you need to rely on the lateral motion of your float within the magnetic level gauge.

The magnetic level gauge is suitable for fluid measurement of various densities. This gauge can also measure fluids of various natures, such as acids, oils, water, and butane. The magnetic level gauge requires little maintenance, and you don’t need to calibrate the equipment constantly. In addition, it provides reliable and precise information for measuring fluid levels.

It is important to specify the magnetic level gauge with your application. The operating conditions are influenced by fluid density, temperature, vessel type, and working pressure. For aggressive fluids, you need to use the higher grade material of alloy 200 or Hastelloy for chamber or float.

7. What are the physical principles of magnetic level gauges?

The magnetic level gauge works on the principle where the liquid in communicating vessel is always at the same level. It follows Archimedes’ principle in which the liquid gets the buoyancy weight that equals the weight of displaced liquid.

The magnetic level gauge has the float in the pipe chamber that moves up and down. The individual flag aligns with the float magnet as the float moves within the piping column. The movement of float rotates the flag that changes the color representing the actual color. Each cylinder will show half of the surface of one color according to the orientation of the magnet.

In a transparent level gauge, a mica sheet is used in which the glass surface protects the liquid level from corrosion or acidic solutions. These sheets are highly suitable for steam-water applications to prevent the damage of the glass.

8. What is the operating principle of magnetic level gauge?

Magnetic level gauge follows the principle of communicating vessels where the level of the measuring chamber will be the same as the level in the vessel. There is a float inside the measuring chamber that has a magnet attached to it. The float will move inside the vessel, and the magnet will turn the flaps of indicating rail. The float should not be pressurized but standard to make the construction of float less dangerous.

The process conditions that can affect the float include density, working pressure, and temperature. A permanent magnet in every indicating rail protects the gauge from shocks, vibrations, and high temperatures. The magnet also protects the gauge from an aggressive environment.

The magnetic level gauge also has the material of plastic, other than stainless steel. The flaps have the material of plastic, aluminum, or stainless steel housing. One side of the flap is white, and the other one is orange. This color distinction makes it possible to see the level even from a distance. The pointers make it possible to see the visual limit on the indicating rail.

You can get the signal from magnetic switches in the magnetic level gauge. More switches will enable the user to create high or low alarms in magnetic level gauges. It has the standard output signal of 4-20mA.

9. What are the advantages of magnetic level gauges?

Following are the key advantage of magnetic level gauge:

• The magnetic level gauge is safer to use because of the absence of fragile glass. There are also fewer chances of potential leakage and chances of breakage under extreme pressure and temperature.
• They are easy to install maintenance-free because, after the installation, the indicator rarely touches the fluid.
• In the magnetic level gauge, the readings are visible even from a far distance of 100 feet.
• The boundary of the magnetic level gauge is made of stainless steel, which makes it strong against corrosion. In addition, the indicators and transmitters are mounted externally, so they are not affected by toxicity.
• The magnetic level gauge has a standard pressurized float system without a magnetic or mechanical rail.
• The magnetic level gauge is insensitive to changes in density and has fully adjustable switches.

10. What are the limitations of magnetic level gauges?

Despite the number of advantages that the magnetic level gauge offers, there are certain drawbacks as well.

• The magnetic level gauge needs calibration when liquid density changes.
• It cannot measures a liquid that contains magnetic particles.
• The magnetic level gauge is suitable for the liquid that has more gravity than the float.
• As the product density decreases, the depth of immersion of the float increases. The depth depends on the float and the material used.
• The float needs thick walls to operate at higher temperatures.

11. What is the role of float in a magnetic level gauge?

The magnetic level gauge measures the level of fluids using a device that can float in high and low-density fluids. The float has the standard stainless steel material, but they are also available in titanium or Hastelloy. The installation of magnet fitting should be at the proper position in the float. The float should be selected carefully for different process conditions.

We can supply the float at the lowest pressure of 380kg/m³. When measuring the aggressive fluid, you should coat the float with a proper lining. The pressurized float is preferable to the open float because the open float can sink. The pressurized floats are suitable at pressure 208 bar at the operating temperature of 375°C with a density of 650 kg/m³.

The float should be fitted in the magnetic level gauge at 360°. All the floats have the standard magnet fitted in them. The float with a magnetic bar can lose the indication rail by movement inside the level gauge, due to which the gauge will not work properly. The floats with Torriodalmagnets are not affected by the movement of the float.

12. What is a plastic magnetic level gauge?

The plastic magnetic level gauge has two lateral sleeves that connect to the vessel. As the fluid level responds with the changes in the vessel, the cylindrical float remains constant. The float counterbalances itself with the density of the medium to maintain buoyancy. There is a disc shape magnetic system that acts through the plastic wall of the chamber. The magnetic force of the float turns through 180° from white to red for increasing level and red to white for decreasing level.

The chamber has a sensitive magnetic contact that gives a binary signal once the float is mounted. You can add reed contact to convert float movement into the signal. However, it is better to use the magnetostrictive sensor that provides accurate output from 4 to 20 mA.

13. What is the range of applications of plastic magnetic level gauges?

The magnetic level gauge made from plastic has a wide range of applications. They are suitable for measuring the aggressive fluid media and level monitoring. You can verify the signals in the control room without assembling work. The distance between the upper and lower lateral connection is measured in millimeters. The measuring tube length is 4000mm, and you can use reference tubes for more considerable lengths.

The magnetic level gauge has a welded bracket for a length of 2000mm or above. The purpose of this welded bracket is to provide extra protection. Slip-on flanges have material of plastic and welding sockets connect to the side of the chamber.

14. What are the primary factors to consider while choosing a magnetic level gauge?

The float and indicator are the most important components while choosing a magnetic level gauge. The strength of the magnetic level gauge is achieved by keeping dirt away from the chamber. In addition, the float changes with the changes in liquid level, so any debris could resist the float from following the liquid level change.

If the float is not manufactured correctly, it will impact the performance of the magnetic level gauge. The gravity of the magnetic level indicator should be less than the density of float. The indicator should be made of stainless steel to make it compatible with the process fluid. You should drain and clean the chamber regularly to prevent any debris. Floats should be inspected periodically to avoid any damage.

15. How to select the magnetic level gauge for your application?

The gravity level measurement needs consideration in the magnetic level gauge properly. If specific gravities differ due to the composition of temperature or pressure, it can affect the readings. The difference between particular gravities should not be greater than 0.1. The magnetic level gauge should not be used in a turbulent or dirty fluid or solid particles in the fluid.

The magnetic level gauge is suitable in applications measuring high pressure, high temperature, and corrosive liquids. Thoroughly understand the three main components of magnetic level gauge before purchasing it. The float, the magnetic chamber, and gaskets will determine the specifications of a certain application. It is essential to take the strength of the magnetic field into account, as the stronger the field, the more efficiently the instrument will work.

16. What are the safety and maintenance concerns of magnetic level gauges?

The safety concerns of the magnetic level gauge are less as compared to the glass gauge. There are lesser chances of breakage if the process fluid is exposed to high pressure and temperature. The magnetic level gauge is made of process metal, primarily stainless steel, making it safer to use. The indicators and transmitters are mounted externally and are not affected by the toxic and corrosive fluid characteristics.

The chemical compatibility with fluid is restricted to float, gaskets, and metallic chambers, while the glass gauges have compatibility issues. The magnetic level gauge requires little or no maintenance. There is no need to check for leakage regularly or clean them daily.

17. How does a magnetic level gauge detect and monitor liquid levels?

The magnetic level gauge works on the principle of communicating vessels. It means that there are separate chambers for low and high-density fluids to flow between the vessels. Changes in the fluid of the primary chamber result in changes in the magnetic level gauge. In addition, the indicator has a magnetized shuttle that moves in response to interior magnets.

This technique relies on the lateral motion of the float within the magnetic level gauge. It is suitable for measuring fluid with different densities, designs, and materials of specific gravity. You can measure fluids including oils, acid, butane, water, and other heterogeneous fluid interfaces. The magnetic level gauge is also preferable to level measurement systems such as sight gauges. You can also customize the unique process demands in the magnetic level gauge with improved buoyant characteristics.

18. What are the types of magnetic level gauges?

Following are some of the common types of magnetic level gauge:

• MG-33p magnetic level gauge

It works on the principle of buoyancy force and pushes and pulls electromagnetic force. The liquid level is visible with the indicator. The controller body and float are made of PVC, which makes it corrosion and acid-resistant. Magnetic effects control the indicator. It is made of aluminum and has a simple design.

The magnetic level gauge is mainly used in tanks that require no pressure strength. It is safe and reliable to use with the electromagnetic principle of lifting and extracting. The magnets in the float enable us to know the liquid change level with the help of white and red flags. It offers easy monitoring and sealing construction and has long product life and low maintenance. You can use this magnetic level gauge in submarine and ship fuel tanks and petrochemical tanks.

This magnetic level gauge is suitable in tanks that can be mounted on side surfaces. The movement of the float responds according to the filling rate of the tank. The mounted magnetic level gauge is mainly manufactured for automation systems. These gauges can work under different densities. They are applicable in all steam and hot water boilers, wastewater systems, petrochemical tanks, submarine tanks, etc.

 

19. What are the features of a magnetic level gauge?

• The magnetic level gauge provides good vibration resistance, convenient installation, and low maintenance cost.
• They are applicable for measuring the liquid level and interface of any medium.
• The magnetic level gauge has the switch for alarm control which provides remote transmission and can be adjusted freely.
• You can adjust the technical parameters with the magnetic steel corrector.
• The magnetic level gauge is suitable for the medium-level detection of various tanks, boilers, and vessels.
• Aluminum or stainless steel housing can be assembled and mounted to the best viewing position.
• The sealed float has the material of stainless steel or corrosion-resistant plastic.

20. How durable and reliable is the magnetic level gauge?

The magnetic level gauge is made of stainless steel that makes this tool durable and anti-corrosive. The material also makes it applicable to different applications. The magnetic level gauge can withstand the toughest conditions such as excessive moisture, system shocks, high pressure, temperature, etc. The buoyancy principle, along with the magnetism, makes it fit for any process.

The magnetic level gauge is applicable in various commercial and industrial applications, including pulp and paper, refinery and chemical industries, gas plants, pharmaceutical, energy, power plant technology, etc.

Conclusion

The magnetic level gauge is the perfect tool for applications where fluid measurement in boilers, tanks, and vessels is required. At Instruthink, we provide customized magnetic level gauges for your specific application. We know the importance of quality equipment for each application, so we focus on quality and accuracy.

We are here to provide you with every single detail about the magnetic level gauge. We are available 24/7 to satisfy our customers.