Measurement and Control Equipment

PVC Magnetic Level Indicator: Safe Level Reading for Acids and Chemicals

Learn how PVC magnetic level indicators show tank levels in chemical and acidic applications with a sealed design, and which data is needed to order one.

ORFA Technical TeamUpdated: Oct 30, 20263 min read

Reliable level monitoring in chemical and acidic applications matters for both process control and safety. Glass gauges carry a breakage risk, while metal gauges are not compatible with some acids. A PVC magnetic level indicator is a sealed, corrosion-resistant bypass level gauge in which all wetted parts are made of PVC.

How Does a PVC Magnetic Level Indicator Work?

The indicator consists of a PVC measuring chamber (bypass) connected to the tank at the top and bottom. According to the principle of communicating vessels, the level in the chamber equals the level in the tank.

A float carrying a permanent magnet floats on the liquid inside the chamber.
As the float moves with the level, it magnetically turns the two-coloured (red-white) flaps on the indicator rail outside the chamber.
Flaps below the float show one colour and those above show the other, so the level can be read easily even from a distance.

Because the indicator connects to the liquid only through the closed PVC chamber, there is no contact or leak path between the liquid and the indicator rail.

Advantages

Chemical resistance: All wetted parts are PVC, suitable for acids and many chemicals.
Sealed design: The indicator rail is fully separated from the medium; no glass to break.
Continuous, easy reading: High-contrast flaps are clearly visible from a distance.
Made to length: Centre-to-centre distance is built to suit the tank.
Different densities: The float is selected for the liquid density.
Easy maintenance: Simple construction with low maintenance needs.

Technical Data

Feature	Value
Material	Indicator flaps aluminium; all other parts PVC
Connection	DN20 PN6 flanged (standard)
Max. pressure	6 bar
Max. operating temperature	70 °C

The pressure resistance of PVC decreases as temperature rises, so the permissible pressure falls as the temperature approaches the upper limit; check both values together before ordering for hot, pressurised applications.

Tip: Although PVC resists most acids, it is not compatible with some organic solvents. State the exact chemical composition of the medium when ordering.

Applications

Storage and process tanks in the chemical industry
Acid and alkali tanks
Chemical dosing tanks in water treatment

Ordering Information

Centre-to-centre distance between the top and bottom connections
Density of the medium
Temperature (and operating pressure) of the medium

Frequently Asked Questions

Why is a PVC magnetic level indicator safer than a glass gauge?

The indicator rail does not touch the medium and there is no glass, so there is no risk of chemical leakage from breakage.

Which dimension is needed for ordering?

The centre-to-centre distance between the top and bottom tank connections, plus the density and temperature of the medium.

Can it be used for hot liquids?

The PVC model is suitable up to 70 °C, with reduced pressure capability at higher temperatures. For hotter applications, stainless steel magnetic level indicators should be chosen.

Conclusion

PVC magnetic level indicators provide sealed, easy-to-read and long-lasting level monitoring for tanks containing chemicals and acids. Ordered with the correct length, density and temperature data, they operate reliably. See our level control devices page for other options.

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