Dwyer V6EPS-S-S-4-S Flotect Flow Switch, SPDT, 1-1/4” SS/SS

Overview

The Dwyer V6EPS-S-S-4-S is a Flotect paddle-type flow switch built to detect flow or no-flow conditions in liquid pipelines, triggering an SPDT snap switch when flow drops below or rises above a set point. Its all-stainless-steel construction (304 SS tee, 303 SS lower body) suits this specific model to corrosive or higher-purity process liquids where a brass or iron-bodied switch wouldn’t be appropriate.

As part of Dwyer’s established V6 Flotect flow switch series, this model is sized for 1¼-inch pipe. Seven Star LLC supplies the Dwyer V6EPS-S-S-4-S to process, water treatment, and utility facilities across Oman and the GCC.

Operating Principle

The V6EPS uses a paddle vane inserted into the flow stream; as liquid flow pushes against the paddle, its deflection moves a magnetic linkage that actuates an SPDT snap switch once flow crosses the calibrated trip point. Because the switching mechanism is magnetically coupled rather than a direct mechanical connection through the pipe wall, the switch body stays isolated from the wetted process side, simplifying sealing and improving reliability over repeated actuations.

Engineering Design of the Dwyer V6EPS-S-S-4-S

This model uses a 301 stainless steel vane, 303 stainless steel lower body, a ceramic magnet, and 301/302 stainless steel hardware, with a 304 stainless steel tee connection sized for 1¼-inch pipe. It carries a pressure rating of 2000 psi (138 bar) and a standard operating temperature range of −4°F to 220°F (−20°C to 105°C), with a high-temperature option extending to 400°F (205°C). The SPDT snap switch is rated 5A at 125/250VAC standard, or 5A resistive/3A inductive at 30VDC on CSA/ATEX/IECEx-certified variants.

Key Features

• SPDT snap-action switch, magnetically actuated
• All-stainless-steel wetted construction (304 SS tee, 303 SS body, 301 SS vane)
• 1¼-inch pipe size, direct tee-mount installation
• Pressure rating 2000 psi (138 bar)
• Standard temperature −20°C to 105°C, high-temp option to 205°C
• Switch rating 5A @ 125/250VAC (standard)
• Hazardous-area certified variants (CSA/ATEX/IECEx) available
• No external power required for switch actuation

Industrial Applications

The V6EPS-S-S-4-S is used for flow/no-flow interlock and alarm applications on pump protection, cooling water circuits, and process liquid lines across Muscat, Sohar, and Salalah, where its all-stainless construction handles corrosive or higher-purity fluids that would degrade a lower-grade wetted material. Its simple, self-contained switching action makes it a low-maintenance alternative to a full flow transmitter where only a go/no-go signal is needed.

Across the GCC’s process, water treatment, and power sectors, the V6EPS is commonly specified to protect pumps from dry-running by shutting down or alarming on loss of flow, and to confirm cooling or lubrication flow is present before allowing equipment to start, all without requiring an external power supply for the switch itself.

Technical Specifications

Selecting the Right V6 Flotect Variant

The Dwyer V6 series is available in several body materials and connection sizes, and the model code shows which build you have. The Dwyer V6EPS-S-S-4-S combines an all-stainless-steel wetted construction with a 1¼-inch tee and an SPDT switch. Choose it when the process liquid, cleaning regime or site specification rules out brass or iron. When replacing an installed switch, compare the full model code on the nameplate with the one ordered, and check the pipe size, the paddle arrangement and the electrical housing required for the area classification.

Installation and Commissioning

• Install the tee so the flow arrow matches the actual flow direction, and give the paddle a reasonable straight pipe run upstream and downstream so turbulence from elbows or valves does not cause false trips.
• Follow Dwyer’s instructions for sizing or trimming the paddle to the pipe. A paddle that is too long can bind, and one that is too short will reduce sensitivity.
• Mount the switch in the orientation allowed by the manufacturer’s instructions, usually in a horizontal line with the switch housing above the pipe.
• Wire the SPDT contacts for the required failure logic. For low-flow protection of pumps or heat exchangers, many engineers use the contact that opens on loss of flow so that a broken wire also gives an alarm.
• During commissioning, vary the flow where possible and confirm that the switch trips and resets at the expected points before putting it into the control or interlock circuit.

Maintenance and Troubleshooting

In service, the main risks are debris or scale fouling the paddle and a buildup of solids in the tee. If the switch no longer resets after flow returns, or chatters at steady flow, isolate the line, remove the switch and inspect the vane for bending, deposits or wear. Check the electrical enclosure for moisture ingress, especially in outdoor and coastal installations, and confirm that the cover gasket and cable entries are sealed.

Applications in Oman and the GCC

Stainless paddle flow switches are widely used in the region on cooling water circuits, chemical dosing lines, desalination and water treatment skids, and pump protection loops in utilities and oil and gas facilities, where corrosive water and high ambient temperatures put pressure on materials.

Why Source from Seven Star LLC

Seven Star LLC supplies Dwyer flow, level and pressure instrumentation to plants across Oman and the GCC. We check the model code against your datasheet before ordering and can combine the flow switch with other instruments for the same project or maintenance shutdown.

Also available: Kawaki FS-II Sight Flow Indicator With Flapper – ANSI 150LB Raised Face

Request a Quote for Dwyer V6EPS-S-S-4-S Flotect Flow Switch, SPDT, 1-1/4” SS/SS

Contact Seven Star LLC for a quotation and availability on the Dwyer V6EPS-S-S-4-S Flotect flow switch and the wider V6 series across Oman and the GCC. Our team can help select the correct pipe size, material, and switch rating for your flow-protection application.