FS2000 Flow Switch

Flow Switch Summary

The FS2000 flow switch provides an economical solution for alarm and limit trip switch applications in process and plant installations. FCI's unique thermal dispersion technology provides exceptionally accurate, reliable, and repeatable flow and no flow detection. The FS2000 flow switches have no moving parts to maintain or foul to ensure long service life and reduce routine maintenance costs. These insertion type flow switches provide a fast response, highly repeatable trip point with a heavy duty SDPT 6A relay contact. The FS2000 is for use in liquid or gas flow applications and is rated for installation in hazardous locations. 


  • Pump protection
  • Seal leak detection
  • HVAC monitoring
  • Lubricant monitoring
  • Chemical injection
  • High flow alarm
  • Fill-drain control


Setpoint Range: 
  • Water:
  •     0.1 FPS to 1.0 FPS [0,03 MPS to 0,30 MPS]
  • Hydrocarbon-based Liquids:
  •     0.1 FPS to 1.5 FPS [0,03 MPS to 0,45 MPS]
  • Air/Gas:
  •     1.0 SFPS to 100 SFPS [0,30 NMPS to 30 NMPS]

Flow Repeatability:
± 10 °F [± 5,5 °C] media temperature change
  • Without temperature compensation: ± 5%
  • With temperature compensation option: ± 1%

For higher repeatability, see FCI FLT93 Series 

Response Time: 0.5 to 2.5 seconds 

  • Aluminum, NEMA 4X (IP66 rated; Single or dual conduit ports).

Agency Approvals:  FM, CSA, CRN, ATEX (24Vde & 24 Vac versions) and CE Mark.

Optional N.I.S.T. Flow Calibration Services
Factory N.I.S.T. calibration in air or water is available as an option for customer specified setpoint(s) or a flow curve based on the media ranges specified above

Flow Element

Materials of Construction: 300 Series stainless steel press fit or 316L all welded. 

Process Connections: 
  • For 300 Series stainless steel: 1/4" male NPT 
  • For 316L stainless steel: 3/4" male NPT 

Insertion Lengths:
  • 300 Series stainless steel: 0.98" [25 mm], 2.23" [57 mm], 3.8" [152 mm] 
  • 316L stainless steel: 1.2" [31 mm] or 6" [152 mm] 
  • Customer specified lengths are available as an option. 

  • Operating Temperature: -40 °F to 250 °F [-40 °C to 121 °C] 

    Operating Pressure: 500 psig maximum [35 bar(g)] 

Control Circuit

Operating Temperature: 0°F to +140° F [-18°C to +60° C] 

Input Power:
DC: 24 Vdc (21.5 V to 26.5 V); 1 watt
AC: 24 Vac (21.5 V to 26.5 V); 1 watt
AC: 100 Vac to 240 Vac; 5 watts maximum

Relay Rating:
SPDT 6A relay, 28 Vdc to 240 Vdc resistive[ATEX approval for 28 Vdc (100 mA)]

Instrument Approval and Ratings – FM and CSA: Explosion Proof for Class I, Div. I, Groups B (alarm relay version only), C, and D; non-incendive for Class I, Div. 2, Groups A, B, C, and D; Dust Ignition Proof for Class II, Div 1, Groups E, F, and G; suitable for Class II, Div. 2, Groups F and G; Class III hazardous indoor/outdoor Type 4 locations; ATEX: (24 Vdc and 24Vac powered units only) II 3 GD EEx nA II T6 T62 °C or II 3 GD EEx nC IIC T6 T62°C; CE marking


  • ATEX
  • CE
  • CSA (Hazardous)
  • CSA (Hazardous Non-Incendive)
  • FM
  • FM (Hazardous)
  • FM (Hazardous Alternate)