Philippines Water & Fire Sprinkler System Contractor & Plumbers Association

21/08/2023

Seminar
Certificate of Attendance
Automatic Fire Sprinkler System - Design

21/04/2019

Automatic Fire Sprinkler System AFSS

21/04/2019

Start your Water refilling station and laundry business now

15/04/2018

Pressure Switch - A pressure switch is a form of switch that closes an electrical contact when a certain set fluid pressure has been reached on its input. The switch may be designed to make contact either on pressure rise or on pressure fall. ... Such sensors are also used in security alarm applications such as pressure sensitive floors.

13/04/2018

Flow Switch Detector

13/04/2018

Water Flow Switch Detector

A water flow detector, commonly produced by System Sensor, is an electro-mechanical device designed to send an alarm to a fire alarm panel and/or fire department when a continuous flow of water occurs through the fire sprinkler system’s piping from an activated fire sprinkler head or leak in the system.

WFD Water Flow Detector by System Sensor

The water flow detector includes a plastic vane or paddle that is installed through an opening (or hole) in sizes two inch through eight inch schedule 10 or schedule 40 fire sprinkler pipe (see diagram below), either vertically or horizontally. If water flow greater than 10 gallons per minute is detected, the vane or paddle triggers a switch sending a signal to an alarm panel and bell.
Picture courtesy of System Sensor

What about false alarms? As you've learned thus far, this device relies on accurately reading the flow of water through a pipe. Yes, as you guessed, water flow is not a constant. Surges in water pressure happen regularly – as an example, ever been in the shower when someone flushes a toilet? Ouch!

System Sensor's water flow detector has a mechanical delay mechanism built in. Essentially this timer, which can be set from 0 to 90 seconds, delays the alarm-triggering mechanism long enough to ensure the change in water flow is not a one-off incident but rather a constant flow resulting from an activated sprinkler or serious leak. If water flow decreases to 4 gallons per minute or less the water flow detector resets.

For optimal performance, water flow detectors should be mounted in an area where there is adequate room to service the device and it will not be damaged by normal nearby activity. As a general rule, the flow switch should be mounted six to seven feet above the ground, on horizontal pipe it should be mounted on the top to avoid rust or particle accumulation from interfering with its operation, and on vertical pipe it should be mounted where there is upward flow of water. Other general rules include mounting the device at least 6 inches from fittings that change the direction of water flow and at least two feet from a drain or valve.

The primary electrical components of a flow switch can be replaced without draining the fire sprinkler system. If a flow switch is showing signs of wear and tear, is leaking, or otherwise non-functional, it should be replaced by a qualified fire sprinkler contractor immediately.

At QRFS, we offer System Sensor flow switches in sizes ranging from 2 1/2" to 8". Combined with our superior customer service and extremely fast shipping, you won't need to look anywhere else when you're in the market for a fire protection flow switch. And as always, they are UL/FM approved and come standard with a 3 year warranty.

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12/04/2018

17/03/2018

Fire Sprinkler system

16/03/2018

Plubming Tools