Xylem-McDonnell & Miller FS7-4 1-1/4″ NPT SPDT Industrial Liquid Flow Switch 119700

Xylem-McDonnell & Miller FS7-4 Industrial Liquid Flow Switch

The Xylem-McDonnell & Miller FS7-4 (Part Number 119700) is a heavy-duty industrial liquid flow switch engineered for reliable flow detection in demanding hydronic, boiler, and process piping systems. Featuring a 1-1/4″ NPT connection and a rugged SPDT snap-action switch mechanism, the FS7-4 delivers precise, repeatable switching performance across a wide range of liquid flow applications.

Key Features

• 1-1/4″ NPT pipe connection for straightforward installation into standard piping systems
• SPDT (Single-Pole, Double-Throw) snap-action switch for reliable make/break control
• Rated for up to 300 PSI maximum working pressure — suitable for high-pressure industrial and commercial systems
• Trimmable bronze paddles allow field adjustment to match a variety of pipe sizes and flow rates
• Industrial-grade construction designed for long service life in liquid flow sensing applications
• Part Number: 119700

Applications

• Hydronic heating and cooling systems
• Boiler flow protection and interlock circuits
• Chilled water and condenser water systems
• Industrial process piping requiring flow verification
• Pump protection and flow proving circuits

Specifications

• Brand: Xylem-McDonnell & Miller
• Model: FS7-4
• Part Number: 119700
• Connection Size: 1-1/4″ NPT
• Switch Type: SPDT Snap Switch
• Maximum Working Pressure: 300 PSI
• Paddle Material: Bronze (trimmable)

The FS7-4’s trimmable bronze paddles make it exceptionally versatile — technicians can cut the paddles to length in the field to optimize sensitivity for the specific pipe diameter and fluid velocity of the application. Trust the McDonnell & Miller name for proven flow switch reliability in commercial and industrial HVAC and process systems.