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686 Floatswitch for Pressure Vessels up to 200 psig

The Model 686S Floatswitch is a float type control which completes an electrical circuit to a pump, valve, alarm or other device, when the liquid in the vessel rises (or lowers) to a pre-determined point.


The Float and Arm are rigidly attached to the dry-film lubricated shaft which rotates in the shaft housing. A bracket at the other end of the shaft actuates the switch. A Viton® O-Ring seals against pressure and leakage along the shaft.

A Teflon® washer separates the metal parts and provides lubricity. If leakage ever occurs, the liquid in the vessel seeps out of the safety vent hole. Thus, it is impossible for the liquid to ever enter the switch housing. The maximum travel of the float between the switch “make” and “break” is 1″ for mercury switches and 1/4″ for micro switches.

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686 Floatswitch for Pressure Vessels up to 200 psig


  • Corrosion Proof: Float and Arm are 304 S.S., Cad Plated Steel Vessel Connection (Other materials available for more corrosive liquids).
  • Explosion Proof: CSA Approved, Class I Group D, Class II Group E, F and G, Hazardous Locations
  • Variety of Switch Outputs: The 686 can be obtained with mercury or micro switch outputs and in various combinations, ie.; SPDT, SPST, DPDT, etc.
  • Adjustments: Nothing to adjust or get out of calibration on the mercury switch. Micro switches can be adjusted from the outside when the floatswitch is installed on the vessel.
  • Simple Installation: On an INTERNAL MOUNT, the float passes through a 2″ nipple. On an EXTERNAL MOUNT, install on 2″ external pipe riser connected to the pressure vessel above the high level and below the low level control points.
  • Long Life: Permanently dry-film lubricated S.S. shaft and Teflon® bearing comprise the only pivot point. Due to large bearing surface area, wear is negligible.


  • Switch Housing: Explosion Proof Cast Aluminum
  • Operating Pressure: 0 to 200 psig
  • Proof Pressure: 400 psig
  • Operating Temperature: -20˚F to +400˚F
  • External Float Housing: Ductile Iron
  • Electrical Connection: 1/2″ Female Pipe Thread
Switch Ratings

686SA, 686SB: SPST Mercury

  • 10 A @120 VAC, 5 A @ 240 VAC
  • 3 A @ 440 VAC

686SC: SPDT Mercury

  • 4 A @ 120 VAC, 2 A @ 240 VAC
  • 1 A @ 440 VAC

686SF: SPDT Micro Switch

  • 15 A @ 125, 250 or 480 VAC
  • /8 HP-125 VAC, 1 /4 HP-250 VAC
  • /2 A @ 125 VDC, 1 /4 A @ 250 VDC

686SG: DPDT Micro Switch

  • 10 A @ 125 or 250 VAC
  • 0.3 A @ 125 VDC; 0.15 A @ 250 VDC

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