Buoyancy Level Switch MS50 by ABB

Overview

The ABB MS50 is a buoyancy level switch designed for accurate and efficient detection of liquid levels in industrial tanks and vessels. Built on the principle of buoyancy rather than the magnetic-float visual indication used by ABB’s KM26 gauge, the MS50 provides a simple yet dependable point-level switch output for alarm and control applications, with a robust mechanical design that ensures stable performance under varying process conditions.

Seven Star LLC supplies the ABB MS50 to chemical processing, oil and gas, water treatment, and power generation operators across Oman and the wider GCC as an experienced supply partner for genuine ABB instrumentation. Every unit is supplied with manufacturer documentation and supported locally with mounting and application guidance.

Operating Principle

The MS50 operates based on the displacement of a float in response to liquid level changes; the resulting mechanical movement is transferred via a magnetic coupling to an external switch mechanism. This design ensures hermetic separation between the process fluid and the switch housing, enhancing safety and reliability by keeping the electrical switch contacts entirely isolated from the process media.

With no need for power supply and minimal moving parts, the MS50 ensures long-term, maintenance-free operation – a straightforward mechanical switch principle that avoids the complexity (and potential failure modes) of an electronic level sensor for simple high/low alarm duty. The switch itself is a magnetically actuated, hermetically sealed reed switch in single-pole double-throw (Form C) configuration with rhodium contacts, rated up to 250 V / 1 A / 100 VA on AC or 125 V / 0.5 A / 100 W on DC, with a deadband of approximately ±0.75 in (1.9 cm) between actuation and reset.

Engineering Design of the ABB MS50

The MS50 is highly resistant to corrosion, pressure, and temperature fluctuations, making it suitable for harsh environments across the industries it serves. Metallic units in 316L stainless steel are rated up to 800 psig at 300°F (55 bar at 149°C), with process temperature from −50°F to 200°F (−45°C to 93°C) standard, extendable to 302°F (149°C); thermoplastic construction (PVC, CPVC, or Kynar/PVDF) is available for lower-pressure corrosive service up to 50 psig, with Alloy 20 or Hastelloy C-276 offered for the most aggressive chemical duty. It supports vertical or horizontal mounting and offers multiple process connections – ¾-inch to 4-inch NPT, or 150# and 300# flanged, including metric DN25–DN150 flange options – allowing for flexible integration into existing systems regardless of a vessel’s specific geometry.

Whether for high- or low-level alarm, pump control, or overflow protection, the MS50 provides precise and fail-safe operation. Its durable construction reduces downtime and ensures long service life, helping industries improve process efficiency and safety with a switch mechanism that has few components to wear out or fail.

Key Features

• Buoyancy-based float mechanism for point-level switching
• Magnetic coupling provides hermetic separation from process fluid
• No power supply required, minimal moving parts
• Highly resistant to corrosion, pressure, and temperature fluctuations
• Supports vertical or horizontal mounting
• Multiple process connections for flexible integration
• Suited to high/low-level alarm, pump control, overflow protection
• Durable construction with long service life
• SPDT (Form C) hermetically sealed reed switch, rhodium contacts, up to 250 V / 1 A AC
• Pressure rating to 800 psig (55 bar) in 316L stainless steel; process temperature to 302°F (149°C)
• Thermoplastic (PVC/CPVC/Kynar) or Alloy 20/Hastelloy C-276 construction for corrosive media

Industrial Applications

The MS50 is used across chemical processing, oil and gas, water treatment, and power generation for high- or low-level alarm, pump control, or overflow protection – applications where a simple, power-free mechanical switch provides dependable point-level detection without the complexity of a continuous electronic level transmitter.

Across Oman’s chemical processing and water treatment sectors, and throughout the wider GCC, Seven Star LLC supplies the MS50 as a trusted supplier of ABB products to facilities in Muscat, Sohar, and Salalah that require dependable, factory-genuine buoyancy level switches with full local support, correctly matched between the metallic, thermoplastic, or exotic-alloy construction the customer’s process fluid actually requires.

Technical Specifications

Request a Quote for Buoyancy Level Switch MS50 by ABB

Contact Seven Star LLC for a quotation on the ABB MS50 buoyancy level switch, with manufacturer documentation and local support across Oman and the GCC.

Related Products

• VEGA VEGAPULS 6X Radar Level Transmitter
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• VEGA VEGAPASS 81 Guided Wave Radar Bypass Interface Sensor
• VEGASWING 61 Vibrating Level Switch
• ABB-Capacitance Level Switch A75 RF

Where the ABB MS50 is used

• Chemical processing tanks
• Oil and gas vessels
• Water treatment tanks
• Power generation plants
• High and low level alarms

Selection checklist for the ABB MS50

• Process fluid
• Fluid density
• Process temperature
• Process pressure
• Wetted material
• Mounting position
• Switch rating
• Alarm or control duty

Installation, commissioning and maintenance notes for the ABB MS50

Mount the switch on the tank or the vessel and wire the switch contacts. Raise and lower the level to confirm the switch point. Check the contacts and the float at regular intervals.

Requesting a quotation for the ABB MS50

Please send the fluid, the temperature and the mounting details. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

MS50 switch type

It is a buoyancy level switch.

MS50 maker

It is made by ABB.

MS50 duty

It detects liquid level at a point in tanks and vessels.

MS50 principle

It works on buoyancy.

MS50 not a gauge

It is not the magnetic-float visual indicator used by the KM26 gauge.

MS50 output

It gives a simple point-level switch output.

MS50 uses

The output serves alarm and control applications.

MS50 float

A float moves as the liquid level changes.

MS50 coupling

A magnetic coupling passes the movement to an external switch.

MS50 separation

The process fluid stays hermetically separated from the switch housing.

MS50 contact isolation

The switch contacts stay isolated from the process media.

MS50 no power

It needs no power supply.

MS50 moving parts

It has minimal moving parts.

MS50 operation

It runs for long periods without maintenance.

MS50 reed switch

The switch is a magnetically actuated, hermetically sealed reed switch.

MS50 configuration

The configuration is single-pole double-throw (Form C).

MS50 contacts

The contacts are rhodium.

MS50 AC rating

On AC the rating is up to 250 V, 1 A and 100 VA.

MS50 DC rating

On DC the rating is 125 V, 0.5 A and 100 W.

MS50 deadband

The deadband between actuation and reset is about 0.75 in (1.9 cm).

MS50 material

Metallic units are 316L stainless steel.

MS50 process temperature

The process temperature runs from -45 to 93 degrees C.

MS50 corrosion

The design resists corrosion and temperature fluctuations.

MS50 documentation

Manufacturer documentation is supplied with each unit.

MS50 support

Seven Star LLC gives local mounting and application guidance.

Switch records for the ABB MS50

Record the switch point, the contact check and the date of each inspection.

Choosing the right ABB MS50 for the fluid

Choose the switch from the fluid density, the temperature and the switch rating the circuit needs.