The most important types of water flow meters and their applications

There are different types of water flow meters available in the market and all of them have unique working principles, costs, and benefits. A water flow meter is used to measure the volume of water flowing through a pipe. There are several types to choose from depending on maintenance needs, applications, price, and so on. In this article, we will know about the four most common types of water flow meters and their functions which will help you choose the right one according to your requirements.

Vortex water flow meters: this is a flow measurement device best suited for flow measurement where the introduction of moving parts present problems. In this flow meter, a sensor tab bends side to side as each vortex flow past, generating a rhythm directly proportional to the volumetric flow rate. The frequency that the vortexes are shed depends on the shape and size of the device’s body. A multivariable vortex water flow meter can measure up to five process variables with one connection such as mass flow, density, pressure, volume, and temperature. These flow meters are made from materials like brass, grade, or plastic. It is ideal for someone looking for low maintenance costs. These devices can also be custom-built according to industrial requirements.

Turbine water flow meters: These water flow meters are the most popular and cheapest way to measure water flow. It measures the speed of water flowing through the pipe with the help of a rotating turbine or piston which is usually in a shunt, propeller, or paddle wheel design. The volumetric flow rate of water is directly proportional to the speed of the rotating blades. But there is one disadvantage to this flow meter, these meters can clog in chunky or dirty water like process water which in turn increases the maintenance cost of the meter. They also require a high flow rate to work well.

Electromagnetic water flow meters: this flow meter uses a magnetic field and faraday’s law of induction to measure the water flow. In this flow meter, the water flows through a magnetic field which creates a charge. So, when the water flows faster, it creates more voltage. The flow meter processes the voltage into the flow rate. These types of meters don’t have great accuracy which makes it hard to use them for custody transfer. They also don’t work well on pure water as they don’t have ions to measure. If you are thinking of purchasing an electromagnetic flow meter, you need to know about the chemical compatibility, potential abrasion, and flow velocity in your application.

Ultrasonic water flow meters: as its name suggests, it uses ultrasound to measure the flow. An ultrasonic meter sends one signal upstream and another downstream. Then the flow meter compares the travel time of both signals to find the flow velocity and this calculation is used to find the volumetric flow rate. It can also measure temperature and energy using the differences between the cold and hot legs.