Nitrogen Vortex Flow Meter

A vortex meter sheds alternating Karman-street vortices off a bluff body in the pipe; the shedding frequency is proportional to velocity, and on-board T+P compensation converts that to Nm³/h directly. The LUGB-VRd version at 1:70 turndown catches the low-flow leakage signature that legacy rotameters or orifice plates sit below-range on. Plants typically waste 15–30 % of total nitrogen on valve-stem weeps, seal-gland drains, and over-tuned blanket regulators; payback from identified leaks runs 6–12 months at most sites.

316L stainless ships standard and covers the full range of plant-utility nitrogen service; blanketing, purging, MAP, instrument backup, and post-vaporiser cryo-sourced supply. Hastelloy C is the option for sour-gas service or high-H₂S streams; specify at quote time with the gas analysis. The vortex-shedding measurement principle is purity-agnostic and the LUGB body alloys are not the limiting factor on either accuracy or contamination.

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.

No; a vortex meter measures volumetric flow, not composition. For O₂ contamination monitoring (critical in blanket and purge service), use a dedicated O₂ trace analyser (zirconia-cell or electrochemical) at the tank ullage return. The vortex meter confirms the nitrogen supply rate fits the design purge budget; the O₂ analyser confirms the protected atmosphere stays below the specified ppm threshold. Combining the two in SCADA gives the full inerting-system health picture.

Custody-transfer regulation applies to the trade of gas between two parties; typically natural-gas billing; and is not the standard for nitrogen in food or pharma. The applicable site-level requirements are documented installation procedure and a traceable calibration certificate; the meter ships with a factory calibration certificate against a primary standard on every order. Site-specific qualification documentation is the responsibility of the integrator or facility owner.

Two typical architectures. (1) Output-sum metering: one LUGB on each PSA output header feeds totalized Nm³ into the plant controller for output capacity, blended purity, and cost-per-Nm³ tracking. (2) Consumer-allocation metering: one LUGB per major consumer (blanket manifold, purge manifold, semi-fab tool group). The delta between PSA output and summed consumer meters is the leakage estimate; usually 8–20 %, and the number the VRd’s 1:70 turndown is engineered to reduce. Modbus RTU is a standard protocol that maps into any DCS with a Modbus driver; no custom driver work.

For a vortex meter the usable velocity range is roughly 3–70 m/s, and the Nm³/h range per pipe size on the datasheet is computed from that window against operating pressure and temperature: Q = v × A × (P₁/P_ref) × (T_ref/T₁). Send DN, operating P and T, and expected peak / idle flow; a flow engineer returns an Nm³/h range, recommended model code, and ballpark price. Below DN25 the application drops below this model; for cylinder-fed brazing or instrument-trace service a small mass flow controller is the right tool.

5–7 business days from the factory for every configuration in this model; standard, VRc anti-vibration, or VRd award-winning version; at any DN, PN rating, output mix, or hazardous-area code. Engineering review on the configurator submission turns around within 4 business hours and locks the model code before production starts.