What is a flow switch in a sprinkler system?

Paddle-type, also known as vane-type, flow switches are used in wet sprinkler systems to detect the flow of water and to send an alarm signal. To minimize false alarms due to pressure surges or air trapped in the sprinkler system, a mechanical delay is often used to postpone switch activation.

What is the function of flow switch?

A flow switch, like all switches, is a device designed to make and break an electric current in a circuit. In an industrial system, a flow switch is essential in monitoring and controlling the flow rate of process media – such as steam, liquids, and gases.

How do you test a sprinkler flow switch?

Locate the inspector’s test valve and slowly open so that the valve is in line with the pipe. Allow the water to flow for about 60 seconds or until the alarm sounds. If connected to central station, call to confirm the signal was received.

Where should a flow switch be installed?

The flow switch should be located in a horizontal section of pipe where there is a straight horizontal run of at least 5 pipe diameters on each side of the flo w switch. The flow switch may be installed in a vertical pipe if the flow is in the upward direction.

What is difference between flow switch and pressure switch?

One visible difference between pressure switches and paddle flow switches is the lack of a paddle in the latter. Pressure switches have no parts that reach the open pipe. It’s this distinction that makes these devices safe for dry-pipe, preaction, and deluge fire sprinkler systems that surge a lot of water pressure.

Is a flow switch a sensor?

A flow switch, sometimes referred to as a flow sensor or flow indicator, is a device used to monitor the flow rate and pressure of liquids, air or other gaseous media through a duct, system or loop.

What is the difference between flow switch and tamper switch?

The two most common kinds of supervisory switches found in most sprinkler systems are tamper switches to monitor the control valves and flow or pressure switches to detect when a sprinkler system flows water.

How far should a flow switch be mounted from the nearest fitting?

Mount the F240EA Pneumatic Liquid Flow Switch in a section of pipe where there is a straight run of at least 5 pipe diameters from the nearest elbow, valve, or other pipe restriction (Figure 7). When mounting the flow switch on horizontal pipe, mount the flow switch within 60 degrees of vertical. See Figure 8.