Skip to content

Inline Piston Flow Switch P397 for Compressors, CNC & Cooling Loops

Inline Piston Flow Switch P397 for Compressors, CNC & Cooling Loops

Paquin is spotlighting our P397 Piston Flow Switch, a compact, reliable inline flow switching for liquids and gases, designed to deliver repeatable switching with minimal pressure loss in demanding industrial environments. 

View the P397 datasheet (PDF)


Built for: HVAC, lubrication, and cooling systems plus compressors, CNC, and general fluid control

Measures: Flow presence and threshold switching from 0.16 to 18.5 GPM (26 GPM Max)

Options: Aluminum or stainless housings, NPT/G ports, optional LED indication, and M12 connectivity 

 

The Problem The P397 Solves

When a pump, compressor, cooling loop, or lube circuit loses flow, downtime (and damage) can follow fast. P397 provides a simple, robust way to confirm flow and trigger alarms/interlocks—without adding unnecessary restriction to the line. 

 

What’s New / Why It’s Different

  • Inline piston design actuates a hermetically sealed reed switch for dependable switching 

  • Low pressure loss: average 4.35 PSI @ 6.6 GPM supports energy-efficient operation 

  • Industrial flexibility: works with liquids and gases, with ¼″–1″ NPT or G female connections 

  • Troubleshooting-friendly: optional 24 VDC LED indicates switch state 

 

Applications

  • Compressor systems, air conditioning systems (HVAC) 

  • Machine manufacturing and CNC machines 

  • Cooling systems, lubrication systems, hydraulics, and water systems

 

Key Specifications (snapshot)

Parameter Value
Flow monitoring range 0.16 to 18.5 GPM
Repeatability 5%
Hysteresis setpoint-dependent; minimum noted 0.132 GPM 
Output Reed switch (24 VDC, 1A) 
Protection class IP65
Media temperature Max 194°F (90°C) 
Pressure rating Aluminum: 725 PSI (50 bar); Stainless: 1450 PSI (100 bar) 
Current <50 mA
Max pressure 435 psi (30 bar)
Pressure loss Avg 4.35 PSI @ 6.6 GPM 
Electrical connection M12 x 1 
LED option With LED (requires 24 VDC) or without LED

 

Ordering & Availability

  • Model: P397; select flow ranges dependent on nominal pipe diameter, housing material, medium, switch logic, and mating connector assemblies (see "Build Your Part Number"). 

Download the data sheet (for full technical parameters and dimensions of the P397)

Visit the product page & request a quote - our team will help you select your exact build.