Overview
The Xylem-McDonnell & Miller FS4-3J (Part Number 114610) is a general-purpose liquid flow switch engineered for reliable flow detection in hydronic heating, cooling, and water system applications. Featuring a 1″ BSPT threaded connection and a Single-Pole Double-Throw (SPDT) switching action, this switch provides accurate flow/no-flow signaling to protect pumps, boilers, and chillers from dry-run or low-flow conditions.
Key Features
- 1″ BSPT threaded connection for straightforward pipe installation
- SPDT (Single-Pole Double-Throw) switch for both normally open and normally closed circuit control
- Rated for up to 160 PSI maximum working pressure
- Includes four interchangeable stainless steel paddles: 1″, 2″, 3″, and 6″ lengths to accommodate a wide range of pipe sizes
- Stainless steel paddle construction for corrosion resistance and long service life
- General-purpose design suitable for water, glycol solutions, and other compatible liquids
- Part Number: 114610
Paddle Selection Guide
The FS4-3J ships with four stainless steel paddles to ensure compatibility across multiple pipe diameters. Select the appropriate paddle based on the pipe size in which the switch is installed:
- 1″ paddle — for small-diameter pipe applications
- 2″ paddle — for standard residential and light commercial piping
- 3″ paddle — for medium commercial pipe sizes
- 6″ paddle — for large-diameter commercial and industrial piping
Typical Applications
- Hydronic heating and cooling systems
- Boiler and chiller pump protection
- Cooling tower and condenser water circuits
- Industrial process water systems
- Pump interlock and flow-proving circuits
Specifications
- SKU: FS4-3J
- Part Number: 114610
- Brand: Xylem-McDonnell & Miller
- Connection: 1″ BSPT
- Switch Type: SPDT (Single-Pole Double-Throw)
- Maximum Working Pressure: 160 PSI
- Paddle Material: Stainless Steel
- Included Paddle Sizes: 1″, 2″, 3″, 6″
