A flow switch is a device that monitors the rate and pressure of liquids, air, or other gaseous media moving through a duct, system, or loop. It is also known as a flow sensor or flow indicator. These switches or sensors may be set to measure flow during a specific time period or to monitor overall flow continuously. A flow meter or indicator is not usually a true flow switch; if the device records and displays data, it is better referred to as a meter or indicator.
How Does a Flow Switch Work?
To understand how a flow switch works and what it does, it's helpful first to identify the essential components of a typical flow switch or sensor.
The main device (a paddle or magnetic trigger of some type) is connected to a circuit and positioned in the channel through which liquid or gas flows. The material passing by moves or rotates this paddle, which delivers a signal reading to a secondary component known as the transducer.
The transducer transforms the raw signal from the paddle and transfers it to the transmitter. The transmitter then compares this reading to a set of parameters and delivers whatever signal or action is required to modify the behaviour of other components and systems.
Flow switches may therefore monitor, report on, and regulate liquid or gas flow rate via a specific component of a system or the whole system, ensuring that flow stays within pre-set parameters. If the rate exceeds or falls below what is required, several activities, such as raising an alarm, activating a pump, diverting flow, and shutting down system components. The actions of a switch are entirely dependent on the kind of switch and the purpose for which it was designed.
A tactile paddle will not be found on every flow switch. Ultrasonic and other non-intrusive counterparts, which work by reflecting a signal off the substance being monitored, are also widely used. This is particularly useful when the medium is contaminated, physically hazardous, or otherwise poisonous, or when having no moving components exposed to continuing wear and tear is preferable.
Rotaflow sensors are simpler devices that measure, restrict, or allow the free passage of a gas or liquid via a tapered tube with a float (or occasionally an electromagnet). Magnetic flow switches are available in a number of designs and may be highly effective in a wide range of applications as long as the medium is somewhat conductive.
Flow Switches Applications
1. Flow Switches for Boilers:
Both water and gas pipelines may have boiler flow switches. Water channels are often designed to keep the boiler from operating under low or no flow conditions. The primary purpose of gas boiler flow controls is to prevent the boiler from starting before any gases have evacuated down the chimney through fans.
2. Flow Control Switches for Pumps:
A pump flow switch is often installed to prevent the pump from running dry in the event of a water supply failure. Because water pumps may quickly overheat or become damaged if left running in low/no flow circumstances, flow switches for pumps often function to cut off the energy to the pump when it isn't getting enough liquid.
3. Flow Switches for Shower Pumps:
A shower pump flow switch helps to maintain the water pressure pushed via the pipework and out of the shower head. They have a mechanical design and may be found on both hot and cold supply channels. The switch is activated when there is a demand for water at the shower head, which completes a circuit and instructs the pump to start functioning. Shower pump flow switches may degrade with time due to limescale, heat, and other reasons and may eventually need to be replaced.
PVL Flow Switches
Pressure Vacuum Level Ltd has been selling high-quality flow switches for over 28 years. PVL provides these devices for various industries.
Don't hesitate to contact us if you have any questions about our flow switches or other products.
Other Products
PVL customers can rely on us for high-quality products. Flow Switches are only a handful of the products we provide customers across the United Kingdom. We are also a significant supplier of Pressure switches and Transducers.
