The CST-MLG magnetic level gauge (also called a magnetic level indicator or magnetic sight glass) provides direct, local indication of liquid level in steam boiler drums, feedwater tanks, deaerators and pressure vessels. The fully welded stainless-steel chamber has no glass in contact with the process, making it safe at high pressure and temperature – the ideal replacement for conventional gauge glasses that break, cloud over or leak.
Built to European requirements (PED, CE), the gauge is available up to PN40 and 250 °C, with centre-to-centre lengths from 100 to 6000 mm. Equipment Industrial Solution Co., Ltd (ISE) supplies the CST-MLG and helps you select the right model for your boiler conditions.
How does a magnetic level gauge work?
Inside the chamber, a float with a permanent magnet follows the liquid surface. Its magnetic field passes through the stainless-steel wall and rotates the bi-colour flags of the external indicator (or lights the LED column): flags above the liquid show red, flags below show green (colours can be customised). Operators can read the level clearly from a distance, even in dimly lit boiler houses.
Advantages of the CST-MLG magnetic level indicator
- No glass in contact with the medium – no risk of broken gauge glass or hot steam leaks.
- Clear, long-distance reading with bi-colour magnetic flags or a 24 VDC LED column.
- Titanium float designed for the actual density, pressure and temperature of the boiler water.
- SS304 chamber (SS316L optional), DN20 – DN50 flanges, PN16 / PN25 / PN40 pressure ratings.
- Optional 4–20 mA level transmitter and high/low level switches for PLC and feed-pump control.
- IP65 enclosure suitable for outdoor installation; stainless-steel springs protect the float during transport and pressure surges.
- Supplied with EN 10204 3.1 material certificates and hydrostatic test report for boiler inspection and insurance.
Applications: boiler water level and pressure vessels
- Drum level indication on water-tube and fire-tube boilers, installed on an external bypass bridle.
- Feedwater tanks and deaerators upstream of boiler feed pumps.
- Condensate recovery tanks and blowdown vessels.
- Local back-up level indication alongside electronic drum level transmitters, as required by boiler safety standards (EN 12952, EN 12953).
- Chemical tanks, oil tanks and pressure vessels in food, textile, paper and chemical plants.
CST-MLG magnetic level gauge specifications
| Parameter | Value |
|---|---|
| Product range | CSTMLG – chamber type, magnetic coupling |
| Indicator | Bi-colour magnetic flags or 24 VDC LED column |
| Centre-to-centre distance | 100 – 6000 mm (to suit drum tapping points) |
| Process connection | DN20 flange as standard (DN25 / DN40 / DN50 on request), drilled to EN 1092-1 |
| Pressure rating | PN16 / PN25 / PN40 |
| Design temperature | –40 °C to +250 °C (contact us for saturated steam above 250 °C) |
| Chamber material | Stainless steel SS304 (SS316L optional) |
| Float material | Titanium (standard for boilers) or stainless steel |
| Ingress protection | IP65 |
| Optional outputs | 4–20 mA transmitter; SPDT reed switches for high/low level |
| Mounting | Vertical, side-side or top-bottom connection |
| Standards | PED 2014/68/EU (CE), RoHS 2011/65/EU, EN 10204 3.1 |
Ordering code
Example: CSTMLG-CC350PN25LED — 350 mm centre-to-centre, PN25, LED indicator.
| Code | Description |
|---|---|
| CST | Manufacturer: CST-Instruments |
| MLG | Magnetic Level Gauge |
| CC350 | Centre-to-centre distance (mm) |
| PN25 | Pressure rating: PN16 / PN25 / PN40 |
| LED / FLAG | LED = 24 VDC LED column; FLAG = magnetic flag indicator |
For boiler applications, please provide the centre distance between the two drum tapping points, design pressure and temperature, and the medium (feedwater / saturated steam / condensate) so we can select the correct float and materials.
FAQ
How is a magnetic level gauge different from a gauge glass?
A gauge glass has glass in direct contact with hot water and can break, cloud or leak. A magnetic level gauge uses a sealed stainless-steel chamber and a magnetic float – no glass – so it is far safer and more durable, and it can also provide a 4–20 mA output.
Can the CST-MLG directly replace an existing boiler gauge glass?
Yes. Simply specify the centre-to-centre distance and flange size of the existing drum tapping points.
Can it be connected to a PLC?
Yes. Add a 4–20 mA transmitter for continuous level measurement, or reed switches for high/low alarms and feed-pump control.
Related products
- CST-FF20 float level switch
- DMS-XLT paddle level switch
- Boiler drum level measurement system
- Liquid level controller relay
Where to buy the CST-MLG magnetic level gauge?
EQUIPMENT INDUSTRIAL SOLUTION CO., LTD (ISE) – Ho Chi Minh City, Vietnam – supplies genuine the CST-MLG magnetic level gauge with technical consulting, fast quotation and on-site commissioning support across Vietnam and Southeast Asia.
Contact us: Sales +84 909 617 185 – Technical +84 979 117 185 – Email: [email protected]
