Measuring the flow rate of liquid or gas passing through a pipe is an essential part of an industrial or commercial process. Gas or liquid cannot go through pipelines without proper regulation and measurement.
Since water is one of the most common fluids used in industrial processes, a water flow meter measures the flow rate of water explicitly.
A water flow meter usually has specific manufacturing specifications. The parameters depend on the type of application, budget limitations, and maintenance.
There are four different types of water flow meters. Each kind has unique specifications that suit specific applications more than others.
Whether to choose one over another is a decision that requires careful consideration. This article takes a close look at each kind of water flow meter and their applications.
Mechanical water flow meters
If cost is a primary concern, mechanical flow meters are the most economical type of water flow meter. The device consists of a shunt, propeller, and paddle wheel which rotates through a turbine to measure flow rate.
The water flowing through the pipe has a speed which is calculated against the rotation of the turbine to determine the flow rate. The water flow rate in volume is proportional to the speed of rotation.
One disadvantage of a mechanical flow meter is its susceptibility to clogging when water is dirty or has large particle contaminants. As such, it may incur high maintenance costs.
Vortex water flow meters
A vortex water flow meter can measure multiple variables such as temperature, density, pressure, mass flow, and volumetric flow. The mechanism uses a sensor that moves from side to side every time a vortex passes by.
This movement creates an output in frequency that is directly proportional to the flow rate in volume. Vortex water flow meters are common in large pipelines.
Ultrasonic water flow meters
As the name implies, this device uses ultrasound for measuring the rate of flow in volume units. The basic ultrasonic water flow meter mechanism takes downstream travel time of a sonic pulse and compares this with the upstream travel time of the same sonic pulse. The time difference becomes the volumetric flow rate unit of measurement.
Magnetic water flow meters
In this type of flow meter, a magnetic field acts as the method for measuring volumetric flow. This magnetic field is responsible for calculating the speed of the fluid flowing through the pipe.
The working principle followed is according to the law of electromagnetic induction where liquid generates a voltage as it passes through a magnetic field.
The faster the flow of the fluid, the higher voltage. Magnetic flowmeters have intermediate accuracy which makes them unsuitable for applications requiring custody transfer.
Moreover, they are not ideal for applications measuring the flow rate of pure water because of the absence of ions vital for magnetic flow meters to function.
In conclusion, each type of water flow meter is compatible with specific applications. Customers need to carefully select the correct type of flow meter by assessing the requirements of the application to ensure the most suitable flow meter is selected.