Flow Switch

Overview

A flow switch is a mechanical monitoring device used to detect the movement of air, steam, or liquid within a piping system. In fire protection systems, flow switches play a critical role by detecting water flow and sending a signal to alarm panels or control equipment.

Function & Operating Principle (As Provided)

Flow switches operate by sensing fluid movement and transmitting a trip signal to another device in the system, such as a pump or alarm panel. This signal may initiate an alarm, start a pump, or shut down equipment to protect the system from damage.

Mechanical elements such as paddles, relays, or reed switches are commonly used to generate the trip signal when flow is detected.

Flow & Level Detection (As Provided)

While flow switches monitor fluid movement, float switches are used to detect liquid levels within tanks. Float switches can control pumps, activate alarms, or provide indication signals when liquid levels reach predefined points.

Use in Fire Protection Systems (As Provided)

In wet pipe sprinkler systems, flow switches are used to detect the movement of water caused by sprinkler activation. When water flow starts, the flow switch sends a signal to the fire alarm control panel, triggering an alarm condition.

Typical Applications (As Provided)

• Fire sprinkler systems (wet pipe)
• Fire alarm activation and monitoring
• Water treatment systems
• Pump and cooling circuit protection
• HVAC and hot water systems
• Industrial process and transfer systems

Advantages & Limitations (As Provided)

• Advantages: When water flow starts, the device sends a signal to the control panel and activates the alarm.
• Disadvantages: Causes a small pressure loss and is primarily used in wet pipe systems.

Connection Types (As Provided)

• Threaded connection
• U-bolt mounting

Technical Specifications (As Provided)

• Working Pressure: 400 psi – 450 psi
• Working Temperature: 0ºC to 49ºC (with water)
• Threaded Sizes: 1” – 2”
• U-Bolt Sizes: 2” – 8”

Compatible Pipe Systems (As Provided)

• Steel water pipes
• SCH 10 – SCH 40 pipes

Application Area (As Provided)

Flow switches are suitable for all wet pipe lines where water flow detection is required as part of a fire protection or monitoring system.

Approvals & Certifications (As Provided)

• UL Listed
• ULc Listed
• FM Approved

Operational Benefits

• Reliable detection of water flow
• Immediate alarm activation in fire events
• Simple mechanical operation
• Compliance with international fire protection standards
• Essential monitoring component for wet pipe sprinkler systems