McDonnell & Miller FS6-1 Switch

The McDonnell & Miller FS6-1 (Part Number 115600) is a high sensitivity liquid flow switch engineered for heavy-duty industrial and commercial applications where precision monitoring is mandatory. Designed with a 1" NPT in-line connection, this SPDT snap-acting switch eliminates the need for a pipe tee, reducing installation complexity and potential leak points. It is specifically optimized for low-flow actuation, making it the industry standard for protecting water treatment systems, electronic circuit cooling loops, compressors, and high-performance booster pumps. With its sealed switch compartment, the internal components remain completely isolated from the process fluid, ensuring operational reliability in demanding environments.

Ruggedly constructed to handle a maximum operating pressure of 100 psi and fluid temperatures ranging from 32°F to 225°F, the FS6-1 provides reliable liquid flow control across diverse HVACR and process cooling platforms. The integrated sensitivity adjustment screw allows technicians to fine-tune the setpoint in the field, ensuring the switch trip point aligns perfectly with system requirements. This McDonnell & Miller flow switch is a critical safety component for preventing equipment damage during low-flow or no-flow conditions in commercial boiler controls and industrial pumping stations.

• In-Line Configuration: Simplifies piping by threading directly into the run, bypassing the need for additional tees.
• Extreme Sensitivity: Capable of actuating at exceptionally low flow rates to protect sensitive bearings and electronics.
• Sealed Snap-Action Switch: The SPDT mechanism is fully isolated from liquid contact, preventing corrosion and electrical failure.
• High Flow Capacity: Designed to maintain low pressure drop even at higher velocities up to 10 feet per second.
• Field Adjustable: On-site calibration is straightforward via the accessible range adjustment screw.

What is the maximum pressure rating for the FS6-1?
The McDonnell & Miller FS6-1 is rated for a maximum operating pressure of 100 psi (7 kg/cm²).

Can this switch be used in outdoor environments?
While the FS6-1 can be used outdoors, it must be protected from direct weather exposure and splashing. For wash-down or NEMA 4X requirements, the FS6-W series is recommended.

Does this switch require a specific mounting orientation?
Yes, it must be installed in a horizontal pipe run with the switch housing in the upright position and at least 5 pipe diameters of straight run on both sides.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.