The BNA model supports a very wide range of process conditions

• Operating temperature: –196 °C to +450 °C.
• Operating pressure: from vacuum up to 400 bar.
• Minimum fluid density: ρ ≥ 340 kg/m3.

So for U.S./Canada installations in chemical, petrochemical, power generation, or process-water applications, the BNA covers most extreme service envelopes without electronics.

The BNA uses a bypass chamber (communicating tube) that is connected laterally to the main vessel via at least two process connections (flanged, threaded or welded). In the bypass chamber:

• A float with a built-in permanent magnet moves with the liquid level inside the bypass.
• On the outside wall of that tube is a magnetic display: either plastic rollers or stainless-steel flaps at 10 mm intervals. The magnetic field from the float causes display elements to flip (white-to-red for rising level, or red-to-white for falling level).
• Because the bypass chamber communicates with the vessel, the level in the chamber corresponds to the level in the vessel.

Why this matters for you:

• No power supply needed — useful for remote U.S. sites, offshore rigs, or when electronics are not desired.
• Visual, direct reading of level without relying on remote transmitters (though transmitters can be added).
• Durable and simple: less electronics means less points of failure, which appeals to maintenance-heavy industries like oil & gas or power.

The BNA is highly configurable:

• Process connections: flanged, threaded or welded are supported
• Materials: a wide variety of different process connections and materials are available, meaning you can adapt for corrosive media or special alloys.
• Additional options: explosion-protected versions; the possibility to mount level transmitters and magnetic switches.

Best practice for U.S. buyers:

• Specify the flange standard (ANSI/ASME, API) if you’re in North America.
• Choose materials suited for your fluid (corrosive, high-temp, high-pressure) — e.g., stainless-steel, exotic alloys.
• If your site requires hazardous-area certification (e.g., Class I Div 2, ATEX), confirm which “explosion‐protected” version applies for U.S./Canada.

According to WIKA, the BNA is suitable for a wide range of industries:

• Chemical, petrochemical (including upstream, mid-stream, downstream)
• Oil and natural gas extraction (on- and offshore)
• Shipbuilding, machine-building, power generation equipment, power plants
• Process water and drinking water treatment, food industry, pharmaceutical industry

For North American buyers:

• Refineries and downstream petro sites in the U.S. Gulf Coast region.
• LNG/CNG terminals, offshore platforms in the Gulf of Mexico.
• Utility power plants and industrial boiler/burner systems in the U.S. & Canada.
• Water-and-wastewater treatment plants in municipal or industrial settings.

Some of the principal advantages of the BNA include:

• No external power supply required: The magnetic display works purely mechanically via the float’s magnet.
• Clear visual level indication: The two-color (white/red) display provides a straightforward reading of level without signal conversion.
• High reliability for demanding conditions: The wide operating limits (–196 °C to +450 °C; up to 400 bar) make it suitable for highly challenging process environments.
• Flexible configuration: Able to adapt to a wide variety of process connections, materials, and explosion-proof versions.
• Low maintenance: With fewer electronics and simpler mechanics, ongoing maintenance can be easier — a plus for remote or critical sites in North America.