Flow Switches

Flow Switches for OEM and Industrial Applications

Accurate flow measurements are critical to good process monitoring and control in many plants. Fit-for-purpose flow switches and flow monitors can help improve process control, reduce plant downtime and maintain safe operations.

Save time and have confidence in your flow measurements by selecting and installing the right flow switch. Explore our extensive catalogue or talk to our expert technical support team for personalised support on specifying the right flow monitoring solutions for your specific process and plant conditions.

Fixed Flow Switches

Adjustable Flow Switches

UHP Flow Switches

Paddle Wheel Flow Switches

What is a Flow Switch and How Do They Work?

A flow switch can be used to perform various functions such as monitoring fluid flow rates through system processes, triggering an alarm on detection of high or low flow, or even activating plant or equipment trips.

The term flow switch usually refers to devices that initiate actions (such as starting or stopping other processes within a system) upon detecting deviations in flow from predefined parameters. A sensor that measures, registers and displays information is more commonly known as a flowmeter or flow indicator.

Flow switches are usually activated through paddle or magnetic triggers that become displaced when a liquid or gas passes through. A signal is then sent to a transmitter via a transducer to output a flow reading. The transmitter compares the reading against set parameters and depending on system requirements, the transmitter can initiate further signals for other process actions. These actions can include automatic shutdowns for pump or system protection, alarms for operator investigation or start-ups of other plant processes.

Read our guide on flow switches to find out more about how they work and how to go about selecting the right switch for your process.

Where are Flow Switches Used?

Flow switches are used in many applications and across many industries, from domestic heating systems to high-hazard chemical processing plants. Some example applications include:

• Laser cooling systems
• Compressed air systems
• Boiler systems
• Swimming pool chlorination systems
• Heating, Ventilation, Air Conditioning and Refrigeration systems
• Plant safety systems
  
  

Types of Flow Switches

Flow switches can be generally split into two category types: in-line or non-invasive. In-line flow switches or meters usually have a moving part like a paddle, float or electromagnet to measure, restrict or pass flow. Non-intrusive flow switches, like ultrasonic types, are particularly useful in applications where the medium is hazardous, contaminated or physically damaging. Using non-invasive flowmeters and switches in this case can prevent the wear down of the exposed parts of in-line instruments and reduce pressure drop in the line. 

We carry an extensive range of flow switches in our catalogue that include piston, shuttle and paddle types as well as electronic non-invasive switches. Find out more about our fixed flow switches, adjustable flow switches and visual indicating flow monitors.

Considerations for Specifying a Flow Switch

Specifying the right flow switches for your process involves a number of considerations. Depending on your system requirements, considerations may include:

• Different flow switch technologies
• Maximum allowable pressure drops
• Line sizes
• Set-point ranges
• Flow ranges
• Design conditions (e.g. temperature, pressure)
• Materials of construction
• Connection options
• Analog/digital
• Maintainability
• Communication protocols
• Cost
• Durability
• Accuracy tolerance
• Physical property compensation requirements (e.g. temperature, pressure)
• Hazardous area considerations (e.g. ATEX rating)
• Space constraints
• In-line vs non-intrusive measurements

From simple to demanding processes, our expert technical team is experienced in helping clients consider the specifications needed to meet system requirements. Some examples include discussions around materials of construction to ensure chemical compatibility and corrosion resistance in harsh environments (e.g. stainless steel, Ryton etc), unique mounting requirements, and physical property and flow setting adjustments.

Achieve accurate measurements and precise process control by specifying and installing the right flow switches. We offer a wide range of robust, high-quality flow switches that can be configured for different fluids, applications and environments. Explore our versatile offering below or get in touch with our experts to discover reliable flow solutions for your specific system requirements.

Flow Switch Explainer Video

For more detailed insights on application examples and industry news, please visit our partner ChemTec’s website here. For a brief overview on how the ChemTec 125 flow switch works, please watch our introductory video below:

FAQs