Flow Switches

Flow switches are a common part of all sprinkler systems. They detect that water is flowing in the sprinkler system and give an electrical signal to the fire alarm control system to tell it that the sprinklers are operating. Multiple switches  will be present in any system design so that the location of the water flow and hence sprinkler operation is also known by the control system.

Typically the activation of the switch will also trip the alarm system if it has not already signalled that a fire alarm has happened. The fact that water has started to flow in the sprinkler pipework is often a more reliable indicator than other means of indication such as breaking the glass of a wall mounted alarm which could happen by accident.

A flow switch is a simple and inherently reliable device. A paddle assembly or vane is mounted inside the water pipework such that any movement of the water, turns the paddles or moves the vane aside and activates an electrical contact. Switches include a delay mechanism so that small changes in water pressure and slight movements of the water don’t trigger false alarms. Typically the flow would have to last several seconds and sometimes for over a minute before the switch sees it as a “real” trigger event.

Potter Flow Switches

We stock a range of Potter Flow Switches, that are VSR vane type alarm switches complete with retard device. They are UL listed, FM and LPC approved and are available in sizes from 1″ to 6″ (25mm to 150mm).

The VSR range contains two single pole switches and an adjustable pneumatic retard. The switches are operated when the downstream flow exceeds 10 GPM / 38 LPM and the delay period set on the retard device.

For pricing and stock availability, please drop us a line or call 0161 428 1180.