Hanla FMS-2V-WS Vertical Float Level Switch

Hanla FMS-2V-WS Vertical Type Float Level Switch

The Hanla FMS-2V-WS is a magnetic float level switch manufactured by Hanla Level Co., Ltd. (Busan, South Korea). Designed specifically for high-vibration marine and industrial environments, the FMS-2V-WS provides primary high-level (LAH), low-level (LAL), and bilge high-alarm detection across shipboard auxiliary tanks, cargo hold bilge wells, ballast systems, and industrial liquid sumps.

As liquid levels rise or fall, the permanent magnet embedded within the float guides along the non-magnetic stainless-steel guide pipe, repelling or attracting the balanced internal switch actuator across a sealed isolation barrier. Because the contact mechanism is completely isolated from the process medium, the switch prevents seal failure, media ingress, and contact carbonization, operating safely in harsh heavy fuel oils (HFO), marine diesel (MDO), bilge slurries, and ballast seawater.

Model Details

• Manufacturer: Hanla Level Co., Ltd. (Republic of Korea)
• Model Series: FMS-2 Series (Magnetic Float Switch)

Technical Specifications

Equipment Compatibility

• Engine Room Alarm Monitoring Systems (AMS / ICMS): Kongsberg K-Chief 600 / 700, Valmet DAMATIC DNA, Wärtsilä Nacos Platinum, Nabtesco M-800 series, B&R / Siemens S7 marine automation racks.
• Bilge & Sludge High Alarm Panels: Cargo hold bilge water ingress detection systems (SOLAS Chapter XII Reg. 12 compliance), engine room port/starboard bilge wells, separator sludge drain tanks.
• Fuel & Lubricating Oil Systems: HFO Settling & Service tanks, MDO/MGO drain collecting pots, Stern tube lube oil gravity head tanks, Crankcase lube oil replenishment tanks.
• Ballast & Grey Water Applications: Peak tank high alarms, cofferdam leak detection, sewage treatment plant (STP) intermediate sump high/low pump triggers.

Applications

• Cargo Hold Bilge Well High Level Alarms (LAH): Early warning detection for bulk carriers and general cargo vessels complying with SOLAS water ingress emergency monitoring.
• Machinery Space Bilge Wells: High-level pump cut-in/cut-out signaling and bilge flood alarm to the ECR centralized monitoring desk.
• Fuel Oil & Lube Oil Service Tanks: Overflow prevention, high-level limit indication, and booster feed tank replenishment control.
• Void Spaces & Cofferdams: Dry-space flood signaling to detect seawater bulkhead penetration or piping rupture.
• Deck Drain & Hazardous Drip Trays: Marine auxiliary skids, purifiers, and fuel oil bunkering manifold spill containment.

Frequently Asked Questions

Can the Hanla FMS-2V-WS be configured for both normally open (NO) and normally closed (NC) alarm loops?

Yes. The switch incorporates a single-pole double-throw (SPDT) microswitch featuring three dedicated wire terminals: Common (COM), Normally Open (NO), and Normally Closed (NC). For fail-safe marine automation where a severed wire immediately triggers a system fault, the NC contact arrangement is typically utilized.

How does the FMS-2V-WS differ from the FMS-2V-WS-T model?

Both switches feature identical internal microswitch ratings, pressure envelopes (10 bar), and temperature thresholds (180°C). The “-T” designation indicates an external manual test lever on the housing. This allows ship engineers to mechanically raise the internal float rod from outside the tank to verify switch contacts and control alarms without opening the tank or introducing liquid.

What is the minimum liquid density required to actuate the switch?

The standard SUS316 stainless-steel float is engineered for marine fluids with a minimum specific gravity of 0.70 g/cm³. It actuates reliably across light diesel fuels (MGO/MDO), lubricating oils, heavy fuel oil (HFO), clean water, and seawater ballast.

Is the Hanla FMS-2V-WS rated for hazardous explosive areas?

The standard FMS-2V-WS is an IP56 weatherproof industrial/marine switch suited for standard engine rooms, pump rooms, cargo holds, and weather decks. When installed in hazardous Zone 0, 1, or 2 environments (such as crude oil cargo tanks or chemical pump rooms), it must either be wired through an approved intrinsic safety galvanic barrier (Ex-ia) or replaced with Hanla’s flameproof/explosion-proof variant (FMS-2V-EX).

What maintenance is required for the internal microswitch?

Because the microswitch compartment is completely isolated from the wet tank atmosphere, the electrical mechanism requires no periodic lubrication or cleaning. Annual maintenance involves verifying terminal screw torque, testing contact resistance, inspecting the cover O-ring, and ensuring the guide tube is free of heavy sludge build-up.