The Dwyer V6EPS-S-D-4-S is a Series V6 Flotect mini-size flow switch with a 303 stainless steel upper and lower body, a DPDT snap switch, and a factory-installed 1-1/4 in NPT 304 stainless steel tee. A free-swinging vane in the flow stream carries a magnet that trips the snap switch through the solid metal switch body, so there are no bellows, springs or seals in the media path. It monitors air, water and other gases and liquids compatible with the wetted materials to 2000 psi (138 bar) and -4 to 220°F (-20 to 105°C) in a weatherproof housing designed to meet NEMA 4 and rated explosion-proof for hazardous locations. The actuation and deactuation points are set by the vane supplied with the tee and are not field adjustable; the published values are approximate and nominal for a horizontal pipe run. Calibration to a specific flow rate is available from the factory as a special-order option.
Best for
- Protecting pumps, motors and other equipment against low or no flow
- Sequencing pump operation and auto-starting auxiliary pumps or engines
- Shutting down liquid-cooled engines and machines when coolant flow stops
- Proving combustion air flow through a heating coil before a burner fires
- Controlling dampers according to flow
- Signalling an alarm when an emergency shower or eyewash station is in use
Magnetic vane actuation
A free-swinging vane attracts a magnet inside the solid metal switch body, actuating the snap switch through a simple lever arm. No bellows, springs or seals sit in the media path.
Weatherproof, explosion-proof enclosure
Weatherproof housing designed to meet NEMA 4 and rated explosion-proof, so the switch can be installed in hazardous locations without a separate purged or pressurised enclosure. See Technical Specifications for the enclosure listing and hazardous location groups.
Fixed set point in a supplied tee
Ships with a 1-1/4 in NPT 304 stainless steel tee and a vane sized to that connection, so the switch drops into the line with no field setup. The set point is fixed; custom calibration is a factory option.
Leak-proof bar-stock body
The switch body is machined from bar stock, and the vane assembly is magnetically coupled rather than mechanically sealed.
Serviceable without draining the line
The electrical assembly can be replaced without removing the unit from the installation, so the process does not have to be shut down.
Rated to 2000 psi
This construction (stainless steel tee) is rated to 2000 psi (138 bar), with a standard temperature limit of -4 to 220°F (-20 to 105°C).
| Service | Gases or liquids compatible with the wetted materials |
| Wetted Materials | Vane: 301 SS; lower body: 303 SS; magnet: ceramic; other: 301, 302 SS; tee: 304 Stainless Steel |
| Upper Body | 303 SS |
| Switch Type | DPDT snap switch |
| Electrical Rating | 5 A @ 125/250 VAC |
| Electrical Connections | 18 AWG leads, 18 in [460 mm] long. Black = common, blue = normally open, red = normally closed |
| Process Connection | 1-1/4 in NPT tee connection |
| Conduit Connection | 3/4 in male NPT |
| Pressure Limit | 2000 psi (138 bar), stainless steel tee |
| Temperature Limit | -4 to 220°F (-20 to 105°C), standard |
| Enclosure Rating | Weatherproof, designed to meet NEMA 4, and explosion-proof. The Series V6 enclosure is listed with UL and CSA for Class I, Groups A, B, C and D; Class II, Groups E, F and G |
| Set Point Adjustment | None. Fixed by the vane supplied with the tee. Custom factory calibration to a specific flow rate is available as an option |
| Mounting Orientation | Any position. Chart flow rates are based on horizontal pipe runs and are nominal values |
| Dimensions | Switch height above tee 5-3/8 in [136.5 mm]; tee Dim. A 3-1/2 in [89 mm], Dim. B 2-1/2 in [64 mm] (per Bulletin E-22 dimension drawing) |
| Weight | 2 to 6 lb (0.9 to 2.7 kg) depending on construction |
| Option-Only Certifications | ATEX, IECEx and KC certification require the -AT, -IEC or -KC option suffix and are not included on this model |
| Media (1-1/4 in pipe) | Actuate | Deactuate |
|---|---|---|
| Cold water | 4.00 GPM (15.17 LPM) | 3.00 GPM (11.3 LPM) |
| Air | 21.0 SCFM (600 LPM) | 18.0 SCFM (540 LPM) |
Approximate actuation and deactuation flow rates for the factory-installed tee. Values are nominal and assume a horizontal pipe run. Units can be factory calibrated to a specific flow rate on request.
What media can the V6EPS-S-D-4-S monitor?
Air, water and any other gas or liquid compatible with the wetted materials: vane: 301 ss; lower body: 303 ss; magnet: ceramic; other: 301, 302 ss; tee: 304 stainless steel.
What flow rate does it actuate at?
In the supplied 1-1/4 in tee it actuates at approximately 4.00 GPM on cold water or 21.0 SCFM on air, and deactuates at 3.00 GPM or 18.0 SCFM. Values are nominal and based on a horizontal pipe run.
Can the set point be changed in the field?
No. Standard V6 models with a factory-installed tee have no set point adjustment, and the published flow values are approximate nominal figures for a horizontal pipe run. For a different set point, order a no-tee model with a field-trimmable vane, a low flow model, or request custom factory calibration to a specific flow rate.
How is the DPDT wired?
The V6EPS-S-D-4-S carries a DPDT snap switch with 18 AWG leads, 18 in [460 mm] long, rated 5 A @ 125/250 VAC. Black is common, blue is normally open and red is normally closed. Normally open contacts close and normally closed contacts open as flow rises to the actuation point.
Is this model ATEX or IECEx certified?
No. The V6EPS-S-D-4-S is the standard explosion-proof construction. ATEX compliance requires the -AT option, IECEx requires -IEC and Korean certification requires -KC, each supplied with a junction box. Units without the AT suffix are not Directive 2014/34/EU compliant and are not intended for use in potentially hazardous atmospheres in the EU.
Can it be mounted vertically?
Yes. The switch can be installed in any position, but the actuation and deactuation flow rates in the charts are based on horizontal pipe runs and are nominal values. Install with the body arrow pointing in the direction of flow.
Specifications from Dwyer datasheet DS-V6 Rev. 4 (1/21) and Dwyer Bulletin E-22, FR# 440805-00 Rev. 18 (8/21). Verified 2026-08-06.
Manufacturer Warranty. Warranty terms are product-specific. Where no different product-specific warranty is supplied with the product, DwyerOmega's standard warranty covers defects in materials and workmanship under normal use for one year from delivery. See the manufacturer's current warranty policy for the governing terms.
Coverage does not extend to damage from mishandling, improper installation, operation outside published ratings, or unauthorized modification. Repairs are to be performed by the manufacturer; units needing repair should be returned to the factory prepaid. ZOT Supply is a Dwyer distributor. Contact us for warranty support and return authorization.
- Type:
- Flow Switch
- Switch Output:
- DPDT
- Product Series:
- V6 Flotect
- Body Material:
- 303 Stainless Steel
- Tee Material:
- 304 Stainless Steel
- Set Point Adjustment:
- Fixed (Nominal)
- Enclosure Rating:
- Weatherproof and Explosion-Proof
- Connection Type:
- NPT
- Connection Size:
- 1-1/4 in
- Pressure Limit:
- 2000 psi
