Product Overview
- The CST-MLG is a bypass-chamber magnetic level gauge engineered to European design and safety standards for continuous level indication in boilers and pressure vessels.
- A guided float with a permanent magnet follows the liquid surface inside a sealed chamber; the magnetic field couples through the chamber wall to rotate a row of bi-colour flags (or light up an LED column), showing red above the liquid level and white/silver below it.
- Because the process fluid is fully enclosed in a welded chamber, there is no glass in contact with the process — eliminating the failure mode of reflex or transparent sight-glass gauges under pressure and thermal cycling.
- Each unit is individually serialised and supplied with material and hydrostatic test certification suitable for boiler-plant inspection and insurance requirements.
- Widely used on steam drums, mud drums, feedwater vessels, deaerators, condensate receivers and blow-down flash vessels.
Features
- Fully welded, glass-free chamber — no sight glass in contact with process fluid.
- Bi-colour magnetic flag column or 24 VDC LED indicator column, readable in low light and from a distance.
- Titanium or stainless steel float, sized and calibrated to the density, pressure and temperature of the service fluid.
- DN20 flanged process connection as standard (DN25 / DN40 / DN50 available on request), rated PN16 / PN25 / PN40.
- Chamber and wetted parts in stainless steel (SS304 standard, SS316L on request) for feedwater and steam-condensate compatibility.
- Optional 4–20 mA magnetostrictive or reed-switch level transmitter, plus adjustable SPDT reed relay switches for high/low level alarm and pump control.
- IP65-rated enclosure, suitable for outdoor boiler-house installation.
- Traceable material certificates (EN 10204 3.1) and hydrostatic test report issued with every unit.
- Stainless steel float-support springs fitted top and bottom as standard, protecting the float during transport and pressure surges.
Technical Parameter
- Model series: CSTMLG (chamber type, magnetic coupled)
- Example model: CSTMLG-CC350PN25LED
- Indicator type: Bi-colour magnetic flag column, or 24 VDC LED indicator column
- Center-to-center length: 100 – 6000 mm (project-specific, per boiler drum tapping distance)
- Process connection: DN20 flanged standard (DN25 / DN40 / DN50 on request)
- Nominal pressure rating: PN16 / PN25 / PN40
- Design temperature: –40 °C to +250 °C (chamber); consult factory for saturated steam service above 250 °C
- Chamber / body material: Stainless steel SS304 (SS316L available)
- Float material: Titanium (standard for high-temperature boiler service) or stainless steel
- Flange material: Stainless steel, drilled to EN 1092-1
- Protection class: IP65
- Power supply (LED variant): 24 VDC
- Optional output: 4–20 mA level transmitter; SPDT reed relay level switches
- Mounting orientation: Vertical, side or top/bottom entry bridle mounting
Industry Application
- Steam drum level indication on water-tube and fire-tube boilers, mounted via external bridle (bypass) piping.
- Feedwater tank and deaerator level indication upstream of boiler feed pumps.
- Condensate receiver and blow-down flash vessel level monitoring.
- Local back-up indication alongside electronic drum-level transmitters, as required by boiler insurance bodies and codes such as EN 12952 (water-tube boilers) and EN 12953 (shell boilers).
Standards & Compliance
- Pressure Equipment Directive (PED) 2014/68/EU — CE marking applied per the assessed conformity route for the ordered pressure and volume category.
- RoHS Directive 2011/65/EU.
- EN 1092-1 flange dimensions and drilling.
- EN 10204 material certification (3.1 certificates available on request).
- Design guidance aligned with EN 12952 (water-tube boilers) and EN 12953 (shell boilers).
- Each gauge carries a permanent stainless steel nameplate with model code, serial number, manufacture year, rated pressure/temperature, CE marking and applicable directive references.
Ordering Code
Example: CSTMLG-CC350PN25LED
| Code | Meaning |
|---|---|
| CST | Manufacturer prefix — CST-Instruments |
| MLG | Product family — Magnetic Level Gauge |
| CC350 | Center-to-center length in mm (example: 350 mm) |
| PN25 | Nominal pressure rating (PN16 / PN25 / PN40) |
| LED | Indicator type: LED = 24 VDC LED column; FLAG = magnetic flag column |
For boiler applications, please provide the drum tapping centre distance, design pressure and temperature, and service fluid (feedwater / saturated steam / condensate) when requesting a quotation, so float buoyancy and materials can be confirmed for the specific service.







