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Flotect Series V4

Flotect Series V4 Vane-Operated Flow Switch

Field Adjustable – Dependable Protection Against Flow Variation or Stopping in Pipelines for Fluids, Gases and Flowing Solids

Flotect Series V4
Flotect Series V4

Rugged and reliable the Flotect Series V4 Flotect flow switch operates automatically to protect equipment and pipeline systems against damage from reduction or loss of flow. The V4 is time tested being installed in thousands of pipelines and processing plants around the world. A unique magnetically actuated switching design gives superior performance. There are no bellows, springs, or seals to fail. Instead, a free-swinging vane attracts a magnet within the solid metal switch body, actuating a snap switch by means of a simple lever arm.

Application Examples

  • Protects pumps, motors and other equipment against low or no flow.
  • Controls sequential operation of pump.
  • Automatically starts auxiliary pumps and engines.
  • Stops liquid cooled engines, machines and processing when coolant flow is interrupted.
  • Shuts down burner when air flow through heating coil fails.
  • Controls dampers according to flow.


Series V4 Features

  • Leak proof body machined from bar stock
  • Choice of custom vane calibrated for your application, Model V4, or field adjustable multilayer vane, Model V4-2-U
  • Weatherproof, designed to meet NEMA 4
  • Explosion-proof
  • Installs directly and easily into pipeline with a threaded branch connection, tee, or flange
  • Can be used in pipes 1-1/2″ and up
  • Electrical assembly can be easily replaced without removing the unit from installation so that the process does not have to be shut down
  • High pressure rating of 1000 psig (69 bar) with the brass body and 2000 psig (138 bar) with the 316 SS body


See Series V4 Specifications

Service: Gases or liquids compatible with wetted materials.
Wetted Materials:
Vane: 316 SS
Body: Brass or 316 SS standard.
Magnet Keeper: 430 SS standard, 316 SS optional.
Options: Other materials also available, consult factory (e.g. PVC, Hastelloy, Nickel, Monel, Titanium).
Temperature Limit: -4 to 275°F (-20 to 135°C) standard, MT high temperature option 400°F (205°C) [MT option not UL, CSA, ATEX or SAA].
Pressure Limit: Brass body 1000 psig (69 bar), 316 SS body 2000 psig (138 bar), optional 5000 psig (345 bar) available with 316 SS body and SPDT switch only.
Enclosure Rating: Weatherproof [meets NEMA 4 (IP65)] and Explosion-proof. Listed with UL and CSA for Class I, Groups C and D; Class II, Groups E, F, and G. ATEX CE 0344 EX II 2 G EEx d IIB T6 -20°C≤Tamb≤75°C, EC-Type Certificate No.: KEMA 03ATEX 2383. SAA: Exd C T6 (T amb=60°C), Zone I. Also FM approved.
Switch Type: SPDT snap switch standard, DPDT snap switch optional.
Electrical Rating: UL, FM ATEX and SAA models 10A @ 125/250 VAC. CSA models: 5A @ 125/250 VAC; 5A res., 3A ind. @ 30 VDC . MV option: 1A @125 VAC; 1A res., .5A ind. @ 30 VDC. MT option: 5A @ 125/250 VAC. [MT and MV option not UL, CSA, FM, ATEX or SAA].
Electrical Connections: UL and CSA models: 16 AWG, 6″ (152 mm) long. ATEX and SAA unit: Terminal block
Conduit Connection: 3/4″ female NPT.
Process Connection: 1-1/2″ male NPT.
Mounting Orientation: Within 5° of vertical for proper operation. Units for horizontal installation (vertical pipe with up flow) available.
Set Point Adjustment: For universal vane: five vane combinations.
Weight: 4 lb 8 oz (1.9 kg).
Agency Approvals: UL, CSA, CE, FM, SAA and ATEX.

Actuation – Deactuation Ranges with Universal Vane
Cold Water – As low as 8.8 – 3.0 GPM (2.0 – 0.7 M3HR) in 1-1/2″ pipe up to 2900-1100 GPM (659 – 250 M3HR) in 20″ pipe.
Air – As low as 6.1 – 25 SCFM (0.03 – .012 NM3/S) in 1-1/2″ pipe up to 14,300 – 5900 SCFM (6.7 – 2.8 NM3/S) in 20″ pipe. (Consult factory for more detailed flow information).

See Options

  • -D – DPDT contacts.
  • -MV – Gold Plated Contacts, options for dry circuits see electrical rating in specification, no listings or approvals).
  • -MT – High Temperature, option rated 400°F (204°C) see electrical rating in specifications, no listings or approvals.
  • -TRI – (increasing flow); -TRD – (decreasing flow), Time Delay Relay, option with 2 SPDT contacts, adjustable from 0-1 to 0-31 minutes. (no listings or approvals).
  • -316 – 316 SS Magnet Keeper, option to replace standard 430 SS.
  • -V – Vertical Up Flow, option for upward flow in vertical pipe.
  • -AT – Atex listed construction.
  • -IEC, IECEx certified construction.
  • -NH, No housing, has no approvals.

Popular Series V4 Models

V4-2-UVane operated flow switch, brass body, universal vane.SPDT
V4-SS-2-UVane operated flow switch, 316SS body, universal vane.SPDT
V4-2-D-UVane operated flow switch, brass body, universal vane.DPDT
V4-SS-2-D-UVane operated flow switch, 316SS body, universal vane.DPDT


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