Model 623

SKU: 623

Flow Switch, Low Flow, Safety Shower and Eye Wash Station Service

The Delta Controls Model 623 dual stage flow switch that actuates at low-flow rates yet does not produce unacceptably high pressure drops at 50 times the actuation rate. The 623 consists of two sections: a flow sensing target and a pressure operated flow bypass valve.

As the flow rate begins to increase from zero, the fluid flows only through a restriction nozzle and impinges against a target, which rotates at the specified flow rate. A switch is magnetically coupled to the target and actuates when the rotation occurs. The switch output is used for alarm or control. The flow valve opens when the flow rate exceeds the actuation rate which allows the additional fluid flow to bypass the restriction nozzle. The pressure drop is thus limited to a low value at high-flow rates.


  • Reactor cooling water loss alarm
  • Low rate alarm in high velocity lines
  • Batch process completion


  • Style: Inline
  • Type: Piston
  • Temperature: ≤ +220 °F (+104 °C)
  • Pressure: ≤ +1200 psig (+83 bar)
  • Actuation: ≥ 0.9 gpm (3.4 L/min) (water)
  • Deactuation:≥ 0.5 gpm (1.9 L/min) (water)
  • Accuracy: ≤ 10%
  • Output: SPDT or DPDT, 5 A
  • Available Wetted Materials: 316 Stainless Steel
  • Housing: 316 Stainless Steel, aluminum
  • Process Connection:
  • Threaded: 1 in to 2 in FPT
  • Flanged: 1 in to 2 in
  • Rating: ≤ 150 lb

Certifications & Approvals

  • Stainless Steel Housing Options Only: Third Party Listed by CSA NRTL/C (USA and Canada)

Required Ordering Information

  • Detailed model number
  • Tag or nameplate detail (if required)
  • Documentation/testing tiers (if required, refer to Additional Resources in the product catalog)

Additional Information


Flow Switch, Low Flow, Safety Shower and Eye Wash Station Service

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