Watch Switched Butterfly Valve

Overview

Watch Switched Butterfly Valves, also known as supervisory switch butterfly valves, are used in fire protection systems to isolate zones and control water flow while allowing continuous monitoring of valve position. These valves function as control valves and are a critical safety component in monitored fire systems.

Function & Operation

In fire protection installations, valves must be continuously supervised to ensure they remain in the correct open position during normal operation. Watch switched butterfly valves are equipped with a supervisory (tamper) switch that provides real-time feedback to the fire alarm or automation system if the valve position is altered.

The valve is operated manually via a handwheel mounted on the shaft, which is connected to a gearbox for smooth and controlled positioning. The integrated supervisory switch allows operators and automation systems to visually and electronically monitor the valve status directly from the valve body.

Design & Installation

These valves are suitable for both indoor and outdoor installations and are commonly used where space-saving solutions are required. Compared to other valve types, butterfly valves occupy less installation space while maintaining reliable performance.

Advantages

• Compact design requiring less installation space
• Integrated supervisory switch for continuous monitoring
• Easy visual inspection of valve position
• Suitable for indoor and outdoor fire protection systems

Disadvantages

• Higher pressure loss compared to some other valve types

Technical Specifications

• Connection Type: Threaded, Wafer, Grooved
• Working Pressure: 175 psi – 300 psi
• Maximum Working Temperature: 120°C
• Dimensions: 1” – 12”

Material Features

• Body: ASTM A 536 Nodular Cast Iron
• Disc: ASTM 395 Nodular Cast Iron (Nickel Coated)
• Spindle: ASTM 583 Type 416 Stainless Steel
• Threaded Box: Cast Iron and Steel
• Gasket: EPDM
• Flywheel: Cast Iron

Application Areas

• Fire sprinkler systems
• Zone isolation in fire protection networks
• Commercial and industrial fire systems
• Buildings requiring supervised valve installations

Certifications & Approvals

• UL Listed
• ULc Listed
• FM Approved