Corrosive Liquid Flow Meter
Strong-Acid & Oxidizing-Chemical Build
Accuracy of ±0.5% of rate
Conductivity threshold ≥ 5 µS/cm
Velocity range 0.3 to 15 m/s
- Line sizes DN6 to DN600 (PTFE liner DN10–DN600, PFA liner DN6–DN600)
- PTFE liner standard for general acid / alkali, PFA upgrade for high-purity service
- Hastelloy C electrode standard for oxidizing acid, Tantalum upgrade for hot HCl and hot H₂SO₄
The Corrosive Liquid EMF measures strong acid, oxidizing chemicals, plating baths, pickle-line wash, and reactor inlet/outlet streams across DN6–DN600 by Faraday’s law. PTFE liner is the chemical-service standard; PFA is the high-purity alternate.
Hastelloy C electrodes are standard for oxidizing acid (HNO₃, H₂SO₄, H₃PO₄); Tantalum upgrades cover hot HCl, hot conc. H₂SO₄, and HNO₃. CNEX Ex d is optional for Zone 1. Lead time 5–7 business days.
Benefits
- PTFE liner (C) standard: DN10–DN600, −25 to +180 °C; handles strong acid, alkali, oxidizing chemicals.
- PFA liner (p) high-purity: DN6–DN600; cleaner inner surface for fine-chemical / pharma-API service.
- Hastelloy C electrode: standard for HNO₃, H₃PO₄, hot conc. H₂SO₄, chloride and Fe³⁺/Cu²⁺ oxidizers.
- Tantalum electrode upgrade: hot HCl, hot conc. H₂SO₄, HNO₃ at elevated temperature.
- ±0.5 % of rate at 0.3–15 m/s for batch billing and acid-consumption accounting.
- CNEX Ex d optional for Zone 1; IP65/67/68 + EMC 2014/30/EU standard. Lead time 5–7 business days.
Typical applications
Four chemical-service zones where electromagnetic measurement with PTFE / PFA liner is the standard specification over Coriolis, ultrasonic, and DP-orifice alternatives.
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Strong-acid pickle line
HCl/H₂SO₄/HF circulations on steel-pickle wash, rinse, spent-acid neutralization; PTFE + Tantalum.
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Electroplating bath
Chrome/nickel/copper/zinc bath circulation, drag-out rinse, replenish feeds DN6–DN200; PFA + Hastelloy C.
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Oxidizing chemical service
Fertilizer HNO₃ recycle, pulp bleaching (H₂O₂, ClO₂), FGD scrubber loops; PTFE + Hastelloy C.
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Reactor & process scrubber
Specialty-chemical, agrochemical, pharma-API reactor inlet/outlet, jacket cooling, venturi scrubber loops.
Flow range by pipe size.
Volumetric flow at chemical-service reference across the 0.3 to 15 m/s velocity range (correct for actual liquid density). DN6 to DN600 range; the table below shows the most common acid / chemical-service sizes.
| DN | Inches | @ 1 m/s (m³/h) | @ 3 m/s | @ 5 m/s | @ 15 m/s (max) |
|---|---|---|---|---|---|
| DN15 | 1/2″ | 0.64 | 1.91 | 3.18 | 9.54 |
| DN25 | 1″ | 1.77 | 5.30 | 8.84 | 26.51 |
| DN50 | 2″ | 7.07 | 21.21 | 35.34 | 106.03 |
| DN80 | 3″ | 18.10 | 54.29 | 90.48 | 271.43 |
| DN100 | 4″ | 28.27 | 84.82 | 141.37 | 424.12 |
| DN150 | 6″ | 63.62 | 190.85 | 318.09 | 954.26 |
| DN200 | 8″ | 113.10 | 339.29 | 565.49 | 1696.46 |
| DN300 | 12″ | 254.47 | 763.41 | 1272.35 | 3817.04 |
| DN500 | 20″ | 706.86 | 2120.58 | 3534.29 | 10602.88 |
| DN600 | 24″ | 1017.88 | 3053.63 | 5089.38 | 15268.14 |
Specifications
| Measurement principle | Faraday’s law of electromagnetic induction |
|---|---|
| Pipe size range | DN6 – DN600 (binding per liner: PTFE DN10–DN600 / PFA DN6–DN600) |
| Accuracy | ±0.5 % of rate standard, ±0.2 % of rate high-accuracy option, ±2.5 % of rate verification grade |
| Velocity range | 0.3 to 15 m/s (1:1500 turndown maximum, typical operation 1–5 m/s) |
| Conductivity threshold | ≥ 5 µS/cm |
| Working pressure | PN10 / PN16 / PN25 / PN40 standard (ANSI 150 to 600 LB), up to PN250 (25 MPa) on request |
| Medium temperature | −25 to +180 °C with PTFE liner; up to +180 °C with PFA liner |
| Ambient temperature | −40 to +60 °C |
| Liner material | PTFE (C) DN10–DN600 standard for chemical service, PFA (p) DN6–DN600 high-purity alternate |
| Electrode material | Hastelloy C standard for oxidizing acid (HNO₃, H₃PO₄, hot conc. H₂SO₄); Tantalum upgrade for hot HCl, hot H₂SO₄, HNO₃ |
| Connection | Flanged (PN / ANSI) standard, sandwich (wafer) optional |
| Output signals | 4-20 mA + HART, RS485 Modbus RTU, pulse, alarm contact, 4G IoT |
| Power supply | 24 V DC, 220 V AC, or battery (lithium, 5-year service life typical) |
| Ingress protection | IP65 standard, IP67 sensor + IP65 converter, IP68 sensor + IP65 converter (submersible option) |
| Hazardous area | Ex d optional for chemical-plant Zone 1 installations |
| Approvals | EMC 2014/30/EU (Annex II), CE, ISO 9001 calibration certificate with each meter |
Selection guide for chemistry-specific configurations
Five decision points decide the right corrosive-liquid build for your service. Selection happens at order; physical install follows the universal install requirements.
- Decision 1: PTFE (C) or PFA (p) liner Default to PTFE (C code) for general strong-acid, alkali, and oxidizing-chemical service from DN10 to DN600 across −25 °C to +180 °C; handles HCl, H₂SO₄, HNO₃, NaOH, FeCl₃, and most industrial chemistries. Step up to PFA (p code, DN6 to DN600) only when surface particulate shedding matters; electronic-chemical, fine-chemical, and pharmaceutical-API service where PTFE’s pore-trapped particulates would contaminate the product stream.
- Decision 2: Hastelloy C or Tantalum electrode Hastelloy C is the standard for oxidizing acid (HNO₃ any concentration, H₃PO₄, hot concentrated H₂SO₄, chloride solutions, Fe³+ / Cu²+ species). Step up to Tantalum only for hot HCl, hot conc. H₂SO₄ above 80 °C, and HNO₃ at higher temperature where Hastelloy C wear life would fall below 12 months. Tantalum carries a meaningful cost premium; reserve for the chemistries where Hastelloy C does not cover the temperature window.
- Decision 3: Concentration-temperature compatibility check For each candidate chemistry, cross-check concentration AND temperature against the liner-electrode combination chart. PTFE handles all concentrations of HCl, H₂SO₄, HNO₃ from ambient to +180 °C. PFA matches PTFE chemical resistance with cleaner inner surface. Hot HCl above 80 °C, hot H₂SO₄ above 80 °C, and HF in any concentration require explicit chemistry-by-name specification at order so the factory ships the right gasket package and chemical-compatibility certificate.
- Decision 4: Conductivity verification (≥ 5 µS/cm threshold) Most acid and oxidizing chemistries sit well above the 5 µS/cm threshold. Verify when ordering: pure organic solvents (toluene, hexane, methanol with trace water below 100 ppm) may fall below threshold and need a different meter principle (vortex-liquid or Coriolis). Mixed aqueous-organic streams: send the actual conductivity measurement at the operating temperature.
- Decision 5: Hazardous-area zone and ingress rating Specify CNEX Ex d at order for chemical-plant Zone 1 installations adjacent to flammable solvent or vapor. IP68 sensor + IP65 converter is the standard for outdoor or washdown chemical-plant locations. For corrosive-vapor atmospheres where the converter housing sees acid mist, specify the optional acid-resistant housing finish at order.
Once the build is selected, the physical install follows the universal install requirements: vertical mounting preferred (electrodes 3 and 9 o’clock if horizontal), ≤10 Ω grounding (sensor housing + pipe + converter, not shared with other equipment), shielded signal cable ≤30 m never parallel with power, valves + bypass at both ends, and never on the pump suction side. Full install requirements in installation manual (pages 089-090).
Frequently asked questions
What is an electromagnetic corrosive-liquid flow meter and why is it the standard for strong acid?+
An electromagnetic corrosive-liquid flow meter measures volumetric flow by Faraday’s law of electromagnetic induction; magnetic-field coils generate a stable field across the pipe bore, and as the conductive acid or chemical (above the 5 µS/cm threshold) flows through the field, an EMF is induced across two electrodes proportional to average velocity. The induced-EMF method has no orifice, no bluff body, and no rotating part exposed to the chemistry; so it is unaffected by the corrosion, abrasion, and scaling that retire turbine, vortex, PD, and ultrasonic-Doppler meters on strong-acid service. PTFE / PFA liner with Hastelloy C or Tantalum electrode covers the chemistry range that almost no other meter principle handles cleanly.
PTFE vs PFA liner; which fits my chemical service?+
PTFE (C code) is the standard for general strong-acid, alkali, and oxidizing-chemical service from DN10 to DN600 across −25 °C to +180 °C. It handles HCl, H₂SO₄, HNO₃, NaOH, FeCl₃, and most industrial chemistries without swell or attack. PFA (p code) is the high-purity alternate from DN6 to DN600; same chemical resistance as PTFE with a cleaner inner surface for low-particulate-shedding applications. PFA is the right choice for electronic-chemical, fine-chemical, and pharmaceutical-API service where the wetted-parts particulate budget matters; PTFE is the right choice for general industrial chemical service where particulate shedding is not a process concern.
Hastelloy C vs Tantalum electrode; when is each the right choice?+
Hastelloy C is the standard electrode for oxidizing acid service; HNO₃ at any concentration, H₃PO₄, hot concentrated H₂SO₄, chloride solutions, and oxidizing species like Fe³⁺ and Cu²⁺ that pit 316L within months. Tantalum is the upgrade for hot HCl, hot concentrated H₂SO₄ above 80 °C, and HNO₃ at higher temperature; service windows where Hastelloy C wear life would fall below 12 months. Tantalum carries a meaningful cost premium and is reserved for the chemistries where Hastelloy C does not cover the temperature window. For general acid service at ambient or slightly higher temperature, Hastelloy C is the standard choice.
Can the meter handle hydrofluoric acid (HF)?+
PTFE liner with Tantalum electrode is the combination for HF service, but specify HF service explicitly at order so the factory uses the appropriate gasket material and ships with a chemical-compatibility certificate. HF attacks glass and silica at trace concentrations, so the meter ships with PTFE-only wetted parts (no glass-encapsulated electrode). Concentration above 70 % HF or temperature above 60 °C requires special-order specification; send the HF concentration / temperature window with the quote request.
What straight-pipe footprint does the meter need?+
The meter measures cross-sectional average velocity directly through the induced EMF; not a single-point sample. Velocity-profile asymmetry from elbows, valves, or reducers does not significantly change the cross-sectional average, so the straight-pipe rule is short: 5D upstream and 2D downstream. This is the key advantage on chemical-plant skids where pipe length is constrained; reactor inlet/outlet runs, electroplating bath circulations, and pickle-line acid feeds drop into existing pipework that vortex (10D / 5D) and orifice (20D / 5D) meters cannot fit.
Are grounding rings required on PTFE / PFA-lined installations?+
Yes; PTFE and PFA are non-conductive, so plastic-lined pipe sections upstream / downstream of the meter break the natural ground reference that the EMF measurement requires. Specify metallic grounding rings at order; they install between the meter flanges and the upstream / downstream pipe flanges and provide the ground reference path. For installations with steel or stainless pipe directly bolted to the meter flanges (no plastic-lined section), grounding rings are not required. The factory ships grounding rings as a configured option; confirm pipe material at quote stage.
What is the lead time and what certification ships standard?+
Standard lead time is 5–7 business days from order confirmation, factory direct. EMC compliance to the EU Electromagnetic Compatibility Directive 2014/30/EU (Annex II) ships as standard. IP65, IP67, and IP68 sensor + IP65 converter ingress ratings are selectable at order. Ex d hazardous-area certification is available for chemical-plant Zone 1 installations adjacent to flammable solvent or vapor.
Need help sizing the corrosive-liquid build?
Send pipe size, chemistry + concentration, temperature, ambient, ingress—engineer replies with sized DN, liner+electrode, model code within 4 hours.