These products can expose you to chemicals including Di(2-ethylhexyl)phthalate (DEHP),
which is known to the State of California to cause cancer and birth defects or other reproductive harm.
For more information go to www.P65Warnings.ca.gov

flow switch™ Compatible with the CTCII and In-Line Monitor/controllers
Click here for detailed image

Shown: CTCIITD with Flow Switch, Flow

Switch Manifold and Mounting Panel



Service: Compatible liquids

Wetted Materials:

Housing and Shuttle: Noryl GFN3 (Polyphenylene Ether and Polystyrene)

Spring: 316 Stainless Steel

Retaining Clip: pH 15-7 MO Stainless Steel

Magnet: Ceramic 1

Temperature Limits: 0 - 194°F/-21 - 90°C

Pressure Limit: 100 psig/6,90 bar @ 70°F/21°C, 50 psig/3,45 bar @ 194°F/90°C

Switch Type: SPST normally open hermetically sealed reed switch

Electrical Rating: 1.5A @ 24 VDC resistive, 0.001A @ 200 VDC resistive, 0.5A @ 125 VAC

Accuracy: ±20%

Electrical Connections: 22 AWG, 18 in./460 mm long

Process Connection: 3/4˝ FNPT

Mounting Orientation: Switch can be installed in any position but the actuation flow rates are based on vertical up flow pipe runs and are nominal values.

Set Point: 1.0 GPM activation on increasing flow

Weight: 4.2 oz./0,119 kg

Deadband: 20% maximum


Note: Standard units are designed with springs for positive return of the shuttle at no-flow condition. This allows the Flow Switch to be mounted in any orientation, but actuation set points vary from stated values.




A periodic check to confirm actuation/deactuation is recommended. These units are not field repairable and should be returned to the factory if service is required.



  1. CAUTION: Mechanical shock or vibration can cause permanent damage to the reed switch. Take care to avoid dropping the unit on hard surfaces or impacting the switch assembly.

  2. Liquid media containing particulate and/or debris should be filtered to ensure proper operation of the FS4 Flow Switch.

  3. Apply Teflon® thread tape or sealant to the 3/4” MNPT pipe threads and install the switch into the piping system. Thread the Flow Switch onto the male pipe thread until hand-tight. Tighten pipe one additional turn. If improper seal results, continue turning pipe into Flow Switch in 1/4-turn increments.
    Do Not
    Exceed 1 Additional Turn.

  4. Connect wiring in accordance with local electrical codes.

  5. Inductive, capacitive, and lamp loads can all create conditions harmful to the reed switch.

    A) Inductive loads can be caused by electromagnetic relays, electromagnetic solenoids, and electromagnetic counters, all with inductive components as the circuit load.

    B) Capacitive loads can be caused by capacitors connected in series with or parallel to the reed switch. In a closed circuit the cable length (150 ft./45 meters or more) to the switch can introduce a capacitance.

    C) Lamp loads can be caused by switching lamp filaments, which have low cold resistance.

In addition to these causes, exceeding any of the maximum electrical ratings can lead to premature or immediate failure. This includes inrush and surge currents greater than the maximum switching current. Use caution when evaluating system loads and current.


Additional Information
Flow Switch™ Data Sheet
(includes specs, options & order info)

click here: PDF

Price List

click here: PDF


Limited Warranty

The Myron L® Flow Switch has a One (1) Year Limited Warranty. This warranty does not apply if the maximum ratings label is removed or if the product is abused, altered, used at ratings above the maximum specified, or otherwise misused in any way. Warranty is limited to the repair or replacement of the Flow Switch only, at our discretion. The Myron L® Company assumes no other responsibility or liability.



                      Site last updated on: 30-Apr-2008 

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