What is a bubble tube level system?

Our Type-L100 product is a self-contained liquid level measurement system. This measurement technique has been around for some time, but due to its simplicity and ability to work in hazardous locations, still maintains a viable and sometimes preferred option in liquid level measurement.   What makes this method so versatile and problem-free in bad environments, is the simplicity of delivering the measuring medium, compressed air.   All you need is a tube to deliver compressed air to the bottom of the vessel or tank, and the rest can be done in a much more suitable environment, away from dangerous or caustic conditions.

The bubble tube liquid level system (BTLLS) works on the basic principle of the pressure a vertical column of fluid creates based on depth. The more liquid above a certain point, the more pressure exerted. The question is, how do you use a long tube to measure depth? There are two critical and basic components of a BTLLS, pressure transducer that creates a pressure and converts it to an electrical signal and a special valve called a constant flow regulator. The constant flow regulator will maintain a small amount of flow (adjustable to suit specific conditions), no matter the pressure that is being exerted against it. In other words, the deeper the liquid, the more pressure that will have to be exerted to maintain this flow. The pressure is then measured by the transducer, converted to an electrical signal (in this case 4 to 20 ma) and then can be converted to the appropriate level measurement using a simple digital scale or local plc. If the tube is kept free of blockages (which can be done with the use of an automatic blowdown cycle), there really is no failure mode of the device within the vessel. All working components are away from potentially harmful environments.

Features and benefits of a bubble tube liquid level system:

• High Accuracy and Stability
• Unaffected by Foam and Vapors
• Excellent for Hazardous, High-Temperature, corrosive or wastewater management
• NEMA 4X Enclosures Available
• Blow Down Capability

Because the “working end” of the bubble system is a tube or hose, it is very easy to use in caustic environments.  Some types of non-contact measurement systems do not work well with liquids that have solids or foam.  The Bubble Tube Level System works based on simple physics and gravity which allows levels to be consistently measured even with foam or solids in the liquid.

Contact the ControlAir sales team so they can help you pick the best L100 for your specific application.