Compressed Air Flow Meter

A vortex compressed-air flow meter sheds alternating Karman-street vortices off a bluff body; the shedding frequency is directly proportional to flow velocity, so no drift and no recalibration. Compressed air typically runs at 20–30 % of a factory’s electricity bill, and 20–40 % of that goes to leaks. A meter quantifies the leak rate (run the system on a weekend; baseline flow is 100 % leak), supports correct compressor sizing, and sub-meters departments for cost allocation.

m³/h (volumetric flow) is the raw volume at line conditions; it changes with pressure and temperature. Nm³/h (Normal cubic meters per hour) is corrected to standard reference conditions (0 °C, 101.325 kPa). For sub-measurement and billing, Nm³/h is the correct unit because it stays independent of varying line pressure. To output Nm³/h the meter needs built-in pressure compensation (option code P).

Depends on the use case. For rough plant-air audits and leak detection, volumetric m³/h is fine; plant air pressure is relatively stable at 0.7 MPa. For sub-measurement, cost allocation, or anywhere the report is in Nm³/h, pressure compensation is required (code P). For temperature-correct Nm³/h on outdoor piping where air temperature varies seasonally, add temperature compensation (code T) as well.

Yes; that is the design intent of the wafer version. It sandwiches between two existing flange faces using longer tie-bolts, so no welding or pipe cutting is needed. The wafer version is available DN15 – DN100 and works with ANSI B16.5 150/300 LB and DIN PN10/16/25/40 flanges. Confirm the existing flange rating on the order so the correct-length tie-bolts ship with the meter.

For plant compressed air at stable pressure, vortex and thermal mass both run ±1 – 1.5 %. Vortex advantages: no drift over time, no recalibration cost, handles higher line pressure, and the pressure-compensation option gives true Nm³/h. Thermal mass advantages: better performance at very low flows (1:100 turndown) and intrinsic mass flow output. For plant audits and sub-measurement on standard pipe sizes DN25 – DN200, vortex is the industry default.

LUGB-VRd is the premium version; ±0.5 % accuracy and 1:70 turndown (vs. ±1.0 % / 1:15 standard). Choose VRd for (1) overnight leak detection, since 1:15 meters cannot resolve the low flows that remain when production is idle, but 1:70 can; (2) cost-recovery sub-measurement where the leakage rate is part of the billed number; (3) air used in custody-transfer or contract-manufacturing settings where ±0.5 % is a contract spec. The VRd version carries the 2024 China Instrument Society Top-10 New Product award. Price delta is typically 25–35 % over standard.

Rule-of-thumb sizing: a typical compressor delivers 0.1 – 0.14 m³/min of free air per kW at 0.7 MPa, so divide nameplate kW by 7–10 to get approximate m³/min. For a tighter number, log inlet pressure and nameplate flow on the compressor for one shift. Once expected m³/h is known, pick the pipe size that keeps line velocity at 10–25 m/s; DN50 covers roughly 70–170 m³/h, DN100 covers 280–700 m³/h. Send the compressor nameplate and receiver pressure for a sized recommendation.

CNEX Ex d IIC T6 Gb (flameproof, Zone 1, gas group IIC, surface-temperature class T6) ships as standard for hazardous-area orders; confirm the zone on the quote. IP65 / IP66 / IP67 ingress protection is available. EMC compliance to the EU Electromagnetic Compatibility Directive 2014/30/EU (Annex II) ships as standard, covering EN IEC 61000-6-1, -6-2, -6-3, -6-4, EN IEC 61000-3-2, and EN 61000-3-3.

5–7 business days from the factory for every configuration in this model; wafer or flanged, standard or VRd, with or without pressure-comp and temperature-comp options. Engineering review on the configurator submission turns around within 4 business hours and locks the model code before production starts.