Level Indicators - Transparent Type - 00000145 - Tubolar Level Gauge Mod. BV-NX | Fival Srl

Fival BV-NX – Tubular Level Gauge with Transparent Glass

The Fival BV-NX is a local visual level indicator for liquids in tanks, auxiliary circuit vessels, and boiler plant installations. The liquid level is read directly through a borosilicate glass tube, requiring no electrical supply or signal converter. This product is referenced as a transparent glass level gauge, type BV-NX.

Construction

Manufacturer documentation lists the instrument as Tubular level gauge mod. VB-NX / BV-NX, Fig. VB, with PN12 configuration and standard supply flanges PN40 DN20. The tubular glass is specified as borosilicate Ø16 × 2.5 mm. For lengths above 3000 mm, intermediate supports are required.

Main Component Materials

• Glass: borosilicate tube
• Tube protection: galvanized metal cover
• Gasket: elastomer
• Bolts: class 8.8
• Nuts: 2H
• Optional: stainless steel B8/A4 bolts/nuts for corrosive environments

NX Connection

The NX version uses plain tube connections and compression fittings between gauge and valves. This configuration is suitable where minor field alignment and straightforward disassembly for glass or gasket replacement are required.

Selection Data

Specification should include:

• center-to-center distance
• connection size and type
• handwheel position (right or left)
• operating pressure and temperature
• process fluid
• requirement for stainless steel wetted parts

Visible glass length is calculated as V = Int. − 90 mm; replacement glass as Int. − 20 mm.

Applications

Used for water, condensate, feedwater tanks, auxiliary vessels, and non-corrosive liquids. For steam, corrosive media, or thermal shock, verify glass, gasket, and pressure/temperature compatibility per manufacturer’s operating chart.

Maintenance

Inspection includes glass cleanliness, crack detection, gasket leakage, condition of protective cover, and operation of isolation/drain valves.