Flanged Vortex Flow Meter

Flanged Vortex Standard Build

Accuracy of ±0.5% VRd
Temperature service −45 to +500 °C
Turndown ratio of 1:70

  • Line sizes DN25 to DN400
  • Flange ratings PN16 to PN160 (ANSI 150 to 2500 LB)
  • Body materials 316L stainless or Hastelloy C
↓ Request datasheet (PDF)
LUGB Vortex Flow Meter; instrument body with display head

The Flanged Vortex Flow Meter is the standard LUGB build for steam, gas, and low-viscosity liquid service across DN25 to DN400 lines. Built-in T+P compensation outputs mass flow directly in kg/h.

316L stainless wetted parts cover most service. Hastelloy C is the upgrade for chloride, acid, or oxidising carry-over. CNEX Ex d IIC T6 Gb available on every configuration.

Benefits

  • VRd accuracy: LUGB-VRd ±0.5 %, 1:70 turndown; 2024 China Instrument Society Top-10 New Product.
  • Built-in T+P compensation: integrated RTD + pressure transducer feed the on-board flow computer, outputting mass flow or Nm³/h directly; no external multivariable transmitter.
  • Pressure class: PN16–PN160 (ANSI 150–900 LB); 4× the wafer ceiling on the same bluff-body geometry.
  • Temperature range: T0–T4 codes cover up to 500 °C; T5 cryogenic option extends down to −190 °C on the same family.
  • Calibration curve: PN16–PN160 share one bluff body, so a DN100 calibration cert applies across the full pressure-class range.
  • Hazardous-area certification: CNEX Ex d IIC T6 Gb (flameproof, Zone 1, gas group IIC) optional.
  • Lead time: 5–7 business days from factory on every configuration.

Wafer vs flanged vs high-T; pressure & temperature comparison

Service zoneTypical pressureTypical medium TRecommended bodyTypical use
Utility≤ PN40≤ 250 °CWafer (LUGB-W)HVAC chilled water, LP steam sub-meter, process water
Saturated & processPN40 – PN100 (H4–H10)T1–T3: up to 400 °CFlanged (LUGB)Saturated main-header steam, petrochem process gas, refinery fuel gas
High-T superheatPN40 – PN160 (H4–H16)up to 500 °C (T4 code)Flanged (LUGB) · VRdSuperheated main-header steam, process tie-in skids
Rule of thumb: pressure × temperature forces the body choice, not either variable alone. A PN40 line at 300 °C is flanged territory even though PN40 alone would still fit in a wafer. Send us the PN and the medium T together and we will confirm the body form in the quote.

Configure your build.

Your Configuration

PF-LUGB-FLG-03-U-S-T-IA-3-316L-H4-H
Pipe sizeDN100
VersionLUGB Standard
Flange ratingH4 · PN40 / Class 300
MediumSaturated/Superheated Steam
Medium TT2 · up to 350 °C
T+P compYes; T+P
Material316L Stainless
Ex protectionEx d (CNEX)
Estimated unit price
Verified after engineer review
$1,842
Total (×1)
$1,842

Flow range by pipe size.

Mass values are for saturated steam at 160 °C / 0.5 MPa (3.26 kg/m³). Volume values apply across gas service. Send your medium, line pressure, and operating temperature on the quote; the engineering team sizes the exact DN with the K-factor curve.

DNInchesVelocity (m/s)Gas volume (m³/h)Saturated steam mass (kg/h)
DN251″4 – 606 – 10020 – 326
DN321-1/4″3 – 709 – 18029 – 587
DN401-1/2″3 – 7014 – 28046 – 913
DN502″3 – 7020 – 40065 – 1,304
DN652-1/2″3 – 7035 – 700114 – 2,282
DN803″3 – 7060 – 1,200180 – 3,912
DN1004″3 – 7090 – 2,000294 – 6,520
DN1255″3 – 70120 – 2,400391 – 7,824
DN1506″3 – 70200 – 5,000652 – 16,300
DN2008″3 – 70350 – 8,0001,141 – 26,080
DN25010″3 – 70550 – 11,0001,793 – 35,860
DN30012″3 – 70800 – 18,0002,608 – 58,680
DN35014″3 – 701,100 – 24,0003,586 – 78,240
DN40016″3 – 701,400 – 31,0004,564 – 101,060

Specifications

Performance

Measurement principleKarman Vortex street
Accuracy class; Liquid±0.5% / ±1.0% / ±1.5% (codes E / A / B)
Accuracy class; Gas/Steam±0.5% / ±1.0% / ±1.5% / ±2.5%
Accuracy; VRd version±0.5% of actual (all media)
Turndown1:10 – 1:70 (1:70 on LUGB-VRd)
Reynolds number range1×10⁴ – 7×10⁶ on the LUGB body

Body & Range

Body formRaised-face flanged body (full flange form)
Pipe sizeDN25 – DN400 (1″ to 16″)
Pressure classH1 – H16 codes: PN16 / PN25 / PN40 / PN63 / PN100 / PN160
A1 – A9: ANSI 150 / 300 / 600 / 900 LB
T0 · standardup to 150 °C
T1 · T2 · T3 · T4up to 250 / 350 / 400 / 500 °C
T5 · cryogenic option-190 °C to +60 °C

Materials & Flange standards

Body material304 default · 316L / Hastelloy C / Titanium alloy optional
Sensor material316L standard · Hastelloy C optional
Sensor elementPiezoelectric crystal, charge-mode
Flange std; ANSIB16.5 RF: 150 / 300 / 600 / 900 LB (A1 / A3 / A6 / A9)
Flange std; DINEN 1092-1: PN16 / 25 / 40 / 63 / 100 / 160
Flange std; JISB2220 RF

Electronics & Compliance

Power24 V DC / 220 V AC / 3.6 V lithium battery
Output4-20 mA (2-wire) · Pulse · RS485 Modbus RTU · HART · 4G IoT
Compensation (codes)NO (none) · P (temperature) · T (pressure)
Hazardous-areaCNEX Ex d (flameproof) · Ex d (flameproof) · combined Ex d + Ex d versions; gas group and T-class confirmed at quotation
Ingress protectionIP65 / IP66 / IP67
CertificationCNEX Ex d (flameproof, Zone 1) · factory calibration cert

Where the flanged build is the standard choice

All four zones sit above PN40 or 250 °C; the wafer ceiling.

🏭

Power-plant auxiliary steam headers

Auxiliary steam at 4–6 MPa, 400–500 °C; flanged LUGB sits on balance-of-plant ahead of the deaerator.

Up to 500 °C · PN40–PN160
🛢

Petrochemical process & refinery fuel gas

Process/fuel-gas headers up to 350 °C in CNEX hazardous zones; PN63–PN100.

Up to 350 °C · PN63-PN100
🔥

Hot-oil & thermal-fluid loops

Heat-transfer fluid up to 400 °C, 1–4 MPa; hydrocarbon, battery-electrode drying, asphalt loops.

Up to 400 °C

LPG vapor & cryogenic distribution

Cryogenic LUGB: −190 °C to +60 °C for liquid-N₂ and low-temperature gas/liquid lines.

Cryogenic · -190 °C to +60 °C

Flange-side commissioning checklist

High-PN flanged service is unforgiving of bolt-torque errors and gasket-material mismatch. The six rules below cover the LUGB install sequence.

  1. Match the flange standard on both sides Confirm upstream and downstream pipe flanges match the meter’s flange standard and rating exactly.
  2. 10D upstream / 5D downstream straight run (LUGB install requirement) Vortex meters need 10 pipe diameters of undisturbed straight run upstream and 5D downstream as a LUGB install requirement.
  3. Use suitable gaskets for high-PN service On PN100 and PN160, use spiral-wound 316L / graphite or kammprofile gaskets; never sheet gaskets.
  4. Cross-pattern torque & second-pass re-torque Apply bolt torque in a cross-pattern in three progressive passes (30% → 60% → 100% target torque).
  5. Insulate the body; not the electronics head Wrap insulation up to the transmitter stem but leave the electronics head exposed.
  6. Verify T+P compensation at cold commissioning Before bringing the line to service temperature, use the HART interface to confirm the T+P module is reading pipe ambient correctly.

Frequently asked questions

When should I pick the flanged vortex flow meter over the wafer version?
Pick flanged whenever the line’s pressure or temperature target exceeds the wafer ceiling. The vortex flow meter working principle (Kármán shedding) is identical between the two body forms; same bluff body, same piezoelectric sensor, same electronics. The wafer sandwich is typically rated to PN40 (ANSI 300 LB) at up to 250 °C; past that, the through-bolt geometry and gasket-crush tolerance run out of margin. Flanged bodies are single-piece castings with raised-face flanges, with clear service up to PN160 (H16) / ANSI 900 LB (A9) at medium temperature up to 500 °C (T4 code on the LUGB body). Power-plant auxiliary steam, petrochemical process gas, refinery fuel-gas headers, and thermal-oil systems above PN40 or 250 °C all belong on this model.
What accuracy and turndown do I get on the flanged body?
The flanged LUGB is the baseline product; ±1.0% of actual on the standard version, ±0.5% of actual on the LUGB-VRd version, named 2024 Top-10 New Product by the China Instrument Society. Turndown is 1:15 standard and 1:70 on VRd. These figures are independent of body form: the wafer and flanged versions share the same bluff body, piezoelectric sensor, and electronics. The flanged body carries that accuracy into high-PN main-header service where the wafer is not rated.
How does the built-in T+P compensation work?
The compensation option codes on the LUGB body are NO (no compensation), P (temperature compensation), and T (pressure compensation). The LUGB-T configuration integrates a Pt1000 RTD and a pressure transducer directly into the meter body, and the on-board DSP applies the density correction internally; no external flow computer required. Output can be set to mass flow (kg/h), normalized volume (Nm³/h), or raw actual volume (Am³/h); configurable over HART or Modbus RTU. If the project specification names a particular gas-equation implementation, send it with the quote and the engineering team will confirm what the current firmware covers.
Do you support cryogenic service on the flanged body?
Yes; the T5 temperature code covers cryogenic service from -190 °C up to +60 °C, for liquid-N₂ and similar low-temperature gas and liquid applications. Specify T5 at quote time if the process sits below the -45 °C floor of the standard T0 range. The cryogenic unit uses the same Karman-vortex measurement principle and the same LUGB electronics; the flow body and sensor materials are selected to the T5 range. Cryogenic orders ship with a factory calibration certificate; dual-point calibration at both ambient and cryogenic conditions is available on request.
Which hazardous-area certifications do you ship?
Standard CNEX Ex d (flameproof, Zone 1) version is available; explosion-proof option from the LUGB Hazardous Area code set, appropriate for hazardous-area petrochem, refinery, and gas-processing service. The specific gas group (IIA / IIB / IIC) and temperature class are confirmed against the project’s process-temperature range and area drawing at quotation. A combined Ex d + Ex d build is available where the sensor needs to be flameproof but the transmitter must sit in a flameproof housing for mechanical protection. All hazardous-area versions ship with certificate copies and installation drawings.
What lead time on high-PN flanged builds?
Every flanged build; PN16, PN25, PN40, PN63, PN100, PN160 (codes H1 through H16), and ANSI 150 through 900 LB (A1 through A9); ships in 5–7 business days. We hold flanged bodies and bluff-body sub-assemblies in stock across all common pressure classes. Send us the size and rating matrix and we will confirm the ship window within one business day.
Which DN should I pick for a flanged vortex flow meter; DN50 or DN100?
Size the meter bore to the actual flow velocity window, not to the pipe. On the LUGB Series the vortex flow meter sits in a 2–70 m/s velocity range for gas and steam; for liquid it is 0.3–8 m/s. A vortex flow meter DN100 handles roughly 90–2,000 m³/h of gas volume (294–6,520 kg/h of saturated steam at 160 °C / 0.5 MPa per the flow-range table); the sweet spot for auxiliary steam headers, reformer net-gas headers, and most utility lines. Drop to DN50 for precision metering on branch lines and small skids where DN100 would force flow below the 1:70 turndown floor. If the pipe is larger than the meter bore, use reducer-expander spools with the 10D/5D straight run measured from the reducer outlet. Send us your flow range and line pressure; we will size the exact DN against the VRd turndown curve in one business day.

Need help sizing the flanged build?

Send per-tag line list; DN, PN/Class, medium T, area class, output. Model codes + pricing in 4 hours. 5–7 days lead time.