Glass-Tube Variable Area Flowmeter

The classic transparent rotameter for low flows of clean liquids and gases: ¼" to 3", 0.25 to 30,000 L/h for water and 0.5 NL/h to 400 Nm³/h for air, to 16 bar and 200 °C, with wetted parts in 316, PVDF, PVC, titanium or Hastelloy and an optional control valve.
Glass-Tube Variable Area Flowmeter
The glass-tube variable area flowmeter is the simplest way to see and set a flow. A precision-bore borosilicate tube carries the scale, the float is visible through the glass, and an optional needle valve at the inlet or outlet adjusts the rate by hand. No power, no straight runs and no calibration drift make it the standard for purge and seal flows, sampling systems, instrument air, laboratory and pilot-plant service.
Sizes run from ¼" to 3" with threaded, flanged or Tri-Clamp connections. Ranges cover 0.25 to 30,000 L/h for water and 0.5 NL/h to 400 Nm³/h for air, depending on model, at pressures up to 16 bar and temperatures up to 200 °C. Wetted parts are selected for the fluid: AISI 316, PVDF, PVC, Moplen, titanium or Hastelloy C, with floats in stainless steel, glass, sapphire or plastics.
Local indication is standard; inductive NAMUR sensors provide minimum and maximum flow alarms. Options include a control valve, a self-regulator for constant flow, a protective cover, panel mounting, special scales in the customer's units, heat tracing and insulation.
Glass rotameters serve chemical, petrochemical, refining, power, water treatment, food and beverage and pharmaceutical plants. For higher pressures, temperatures or opaque fluids, specify the metal-tube version.
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