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High-Pressure Magnetic Flow Meter
A magnetic flow meter built for pressures from 10 to 42 MPa, where a standard mag body would not hold. With a heavy flange and a reinforced bore it meters conductive water and chemicals on a high-pressure line, such as oilfield water injection, to plus or minus 0.3%.
- Pressure: 10 to 42 MPa
- Size: DN15 to DN150
- Accuracy: plus or minus 0.3% / 0.5%
- Output: 4-20 mA; RS485 / HART / Profibus
- Ex: explosion-proof option
Overview
A high-pressure magnetic flow meter measures conductive liquid on a line that runs well above the 1.6 to 4 MPa a standard mag meter is rated for. Its body, flanges and the seal behind the lining are built for 10 to 42 MPa, so it holds where an ordinary mag would leak or fail. The measurement is the same Faraday principle with no moving parts and nothing in the bore, and it reads to plus or minus 0.3% on DN15 to DN150.
That makes it the meter for oilfield water injection, high-pressure dosing and hydraulic-pressure water lines, where the flow has to be metered at the working pressure and a wetted turbine or orifice would wear or clog. It outputs 4-20 mA with RS485, HART, Modbus or Profibus, and an explosion-proof build covers a classified area.
Features
Why a high-pressure mag meter suits a pressurised line:
10 to 42 MPa
A reinforced body and heavy flanges hold pressures far above a standard mag meter.
No moving parts
Nothing in the bore to wear or clog at pressure, unlike a turbine or an orifice.
0.3% accuracy
Reads to plus or minus 0.3%, so injection and dosing volumes are metered, not estimated.
Tough lining and electrodes
PFA, F46 or polyurethane lining and Hastelloy or titanium electrodes for brine and chemicals.
Explosion-proof option
An Exd converter and Ex sensor cover an oilfield or chemical classified area.
Fieldbus outputs
4-20 mA with RS485, HART, Modbus and Profibus-DP for an injection control system.
Working principle
A magnetic flow meter works by Faraday’s law: a conductive liquid moving through a magnetic field generates a voltage proportional to its velocity, read by electrodes flush with the lining and scaled to flow. Pressure does not affect the measurement, since the voltage depends on velocity and field, not on pressure, which is why a mag meter is well suited to a high-pressure line once the body can hold the pressure.
What the high-pressure version adds is mechanical: a thicker body, a high-class flange and a lining seal that resists being pushed out at 42 MPa. The liquid still has to conduct, above about 5 microsiemens per centimetre, so it suits injection water, brine and aqueous chemicals, not oil or gas.
Technical specifications
| Parameter | Specification |
|---|---|
| Diameter | DN15 to DN150 |
| Working pressure | 10 MPa to 42 MPa |
| Accuracy / flow rate | Plus or minus 0.3% or 0.5%; 0.5 to 10 m/s |
| Medium / conductivity | Conductive liquid, above 5 uS/cm |
| Lining | PFA, F46 or polyurethane rubber |
| Electrode | 316L, Hastelloy B or Hastelloy C |
| Output / communication | 0-10 mA or 4-20 mA; RS485, HART, Modbus, Profibus-DP, GPRS |
| Explosion-proof | Sensor Ex ia IIC; converter Ex d IIC T4 |
| Converter | TSM-1 or TSM-2 |
| Protection | IP65 / IP67 |
Pressure rating and selection
The body is built and tested to a working pressure between 10 and 42 MPa, so the right rating is the one above your line pressure with margin for surge. A standard mag meter, rated to 1.6 to 4 MPa, is the cheaper choice on a normal line, and a high-pressure version is for water injection, high-pressure dosing or a hydraulic water circuit. Match the flange class to the rating, specify the lining and electrode for the liquid, and add the explosion-proof build where the area is classified.
Installation
Fit the meter on a full pipe with the electrodes on the horizontal axis, on a straight run of about five diameters upstream and three downstream. Use flanges and bolting rated to the working pressure, torque to spec, and earth the meter to the pipe both sides so the small signal is clean. Set the pipe size and units, confirm the empty-pipe alarm, and pressure-test the joints before commissioning.
Applications
- Oilfield water injection and water flooding
- High-pressure chemical and polymer dosing
- Hydraulic and high-pressure water circuits
- Reverse-osmosis high-pressure feed
- Mining and process lines above standard pressure
An oilfield needed to meter injection water on lines running at tens of megapascals, where a standard mag meter could not hold and a wetted meter would wear in the brine. High-pressure magnetic flow meters rated above the line pressure metered each injection point to plus or minus 0.3%, with no moving parts in the bore and an explosion-proof build for the area.
Related products
Magnetic Flow MeterStandard full-bore mag meter for water, slurry and chemicals to plus or minus 0.5%.
Insertion Magnetic Flow MeterLow-cost probe for large water and sewage mains, DN300 to DN3000.
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FAQ
What pressure can a magnetic flow meter handle?
A standard mag meter is rated to about 1.6 to 4 MPa. A high-pressure version is built to hold 10 to 42 MPa, with a reinforced body, a high-class flange and a lining seal that resists being pushed out at pressure.
How does a high-pressure magnetic flow meter work?
By the same Faraday’s law as any mag meter: the conductive liquid generates a voltage proportional to its velocity. Pressure does not affect the measurement, so once the body holds the pressure the meter reads as accurately at 42 MPa as at low pressure.
Can a magnetic flow meter be used for oilfield water injection?
Yes. Injection water and brine conduct, so a high-pressure mag meter rated above the line pressure meters them with no moving parts to wear in the brine. An explosion-proof build covers the classified area.
How accurate is a high-pressure magnetic flow meter?
It reads to plus or minus 0.3% or 0.5% over 0.5 to 10 m/s, the same as a standard mag meter, since the high-pressure build changes the body, not the measurement.
Request a quote
Tell us the working pressure, the pipe size and the liquid, and we configure one meter rated above the line, not a shelf part.