Blade-Style Flow Switch

Blade Style Flow Switch

Since the mid 1980’s these blade-style flow switches has been used by some of the largest companies in the fluid control industries as well as Pool & Spa. It has several factory adjustable parameters that provide the flexibility to meet the requirements of almost any application.

The blade-style switch verifies fluid flow, typically in conjunction with another device. For example in a chiller it prevents the system from freezing, and in most of swimming pool salt chlorine generators it has been used to verify sufficient flow before the generator is energized. In a spa or hot tub it ensures sufficient flow to prevent the water heater from a meltdown, and at home it turns on the water disinfection system when someone is getting a glass of water.

Typical Working Fluids

For use in a broad spectrum of industrial fluids, such as:

  • Cooling Tower Water
  • Water (pools, spas, saltwater, pure, tap, etc.)
  • Glycol Solutions Lubricating Oils
  • Mild Acids Gasoline
  • Plating Solutions JP-4

Standard Features

–  Max. flow may be five times normal flow.
–  Positive stop eliminates fatigue effects of turbulence, vibration and flow surge on flow detecting element.
–  Very low pressure drop – typically less than 1.0 psig at normal flow rate.
–  Small size and low profile provides easy mounting in crowded installations.
–  Power the driving coil of small ice cube relays as well as some 30A power relays.
–  Switches 5VDC to 240VAC.
–  Switch employs magnetic coupling.
–  Can be used in 3/4″ inch to 6 inch pipe


Flow Range 0.7–590 GPM (2.6–2,233 L/m)
Working Temp 200˚F (93˚C) Maximum
Working Pressure 250 psi (1.724 kPa)
Process Connection 3/4″ NPT
Electrical (Reed) Switch SPNO (single pole normally open) 0.5A*
Enclosure NEMA 4X / IP 66

In Chemical Processing:

  • Fluid Blending Systems
  • Liquid Transfer
  • Heat Transfer Fluids
  • Monitor Filter Clogging
  • Liquid Scrubbers
  • Starting back-up pumps
  • Monitoring pump output, valve position, systems flow status

In Pool and Spa:

  • Protect water heater in Spa
  • Protect water heater in Pools
  • Turn on Salt Chlorinator
  • Turn on UV System
  • Turn on Ozone System

Monitoring flow of coolant supplied to:

  • Brakes and Clutches
  • Emergency Wash-Down Showers
  • Computer Systems
  • Marine and Stationary Engines
  • Diodes, SCRs, Triacs, etc.
  • RF and Radar Transmitters
  • Electromagnets
  • Spot welders
  • Fire Sprinkler Flow Alarms
  • Transformers
  • Lasers
  • Vacuum Systems

In Water Treatment:

  • Irrigation Systems
  • Salt and Fresh Water Systems
  • Chemical Feed Pump Control