Coriolis flow meters for custody transfer

The meter's measuring tubes oscillate at their resonant frequency. Flow through the tubes twists the oscillation: the Coriolis effect separates the phases at the inlet and outlet, and that phase difference is converted into mass flow. Mass readings come directly, with no correction for density or temperature.

At product receipt and dispatch points: crude and sales oil, petroleum products, gas and LPG measured for settlements between supplier and customer. These include custody transfer units (UUK, UKU), oil quantity and quality metering systems (SIKN), tank farms and transshipment terminals.

The meter tracks mass flow and totalizes mass; the same point also gives density over 650–2000 kg/m³ and fluid temperature. One instrument covers duties that would otherwise need a volumetric meter plus a flow computer and separate density and temperature sensors.

Mass is measured directly rather than computed from volume and density. A turbine or ultrasonic custody transfer installation relies on correctors and regular laboratory density data; a Coriolis meter does not, cutting the number of instruments and error sources on the skid.

Free gas is the main factor limiting liquid accuracy, so the metering section is engineered with free gas kept to a minimum. Cost grows with line size: on large diameters the meter is more expensive than volumetric options. High pressure and aggressive media call for a dedicated execution — checked against the datasheet.

A high water cut does not disturb the reading: the meter tracks mass rather than volume, so water in the blend leaves the result unchanged, and the skid keeps its SIKN scheme. What does matter is free gas — the metering section is laid out to keep its content minimal.

All of them are on the list of supported media, together with lubricating oils. Highly viscous products, fuel oil included, call for a straight-tube L sensor; where the product tends to solidify, an isothermal jacket is added.

Gas service is available: the allowable error for gas is ±0.5–1.0% depending on line size, so natural gas and similar streams can be measured. Gas condensate is handled in the liquid phase by standard executions; complex gas–liquid regimes are reviewed separately against actual flow data.

For liquefied gas service the meter is set up for the liquid phase of propane, butane and their blends, with a pressure-rated execution and a flameproof ME100 or ME200 transmitter. The "LPG" page describes this duty range in more detail.

Media containing hydrogen sulphide call for tube materials with higher corrosion resistance: Hastelloy C276/C4, duplex, 904L, titanium or tantalum. The choice follows the composition and temperature, so attach a fluid analysis to the datasheet.

Where viscosity is high, a straight-tube L sensor does the job; for waxy crudes and heavy fractions that set at low temperature, an isothermal jacket (option 19S) maintains the medium temperature.

Pick by duty. U-shaped: universal, DN03–DN250, for custody transfer and process streams. L: straight tube, DN08–DN50, for viscous media and cleaning duties. W: compact, self-draining, DN08–DN100, up to 10 MPa. The final choice follows the medium, flow rate and installation.

The pressure line-up has three levels — standard rated to 10 MPa, P reaching 45 MPa on main sizes and PK reaching 96 MPa. The exact maximum for each DN sits in the type description tables; skid pressure guides the choice.

For a typical skid we recommend a U-shaped sensor DN40–DN250 with ±0.1% accuracy plus an ME200 Ex transmitter with RS-485 Modbus and HART. This set covers crude and product metering: metrological documents come with the meter, and data reach the SIKN over a digital interface.

Flanged (GOST, ANSI, DIN) or threaded connections — the set depends on line size and sensor execution. Connection type and mounting dimensions are agreed before the order, so the meter fits the existing or designed piping.

Two ways to start: fill in the datasheet or go through the online configurator — medium, flow, pressure, temperature, connection, hazardous-area requirements. Based on that we propose the execution and issue a quotation. What sets the price is the combination of line size, materials, pressure rating and Ex execution.

In many cases yes, without welding: we match process connections and mounting dimensions. Compatibility with meters installed earlier, including Micro Motion and Endress+Hauser, is checked against mounting dimensions and interfaces — send a piping drawing or a nameplate photo.

Custody transfer service uses accuracy from ±0.1%. Across the family, liquid accuracy sits between ±0.1% and ±1.0% depending on line size; gas accuracy is ±0.5–1.0%. Calibration is individual, on a flow calibration rig.

Entry under No. 98506-26 gives the meter the right to be used in the sphere of state metrological regulation: custody transfer, SIKN systems, settlements between supplier and customer. The metrological documents are published on the website.

Removal is optional: verification can be performed on a flow calibration rig with reference meters, or on site — with provers, without taking the meter off the line. The order and interval are set by the approved verification procedure; the company also supplies pipe provers and compact provers.

A 100:1 turndown means rated accuracy is held from the top of the flow range down to the smallest rates. That reserve pays off where the load is uneven — transshipment, batch pumping, night-time minimums — keeping mass totals correct in every mode.

Straight runs are not specified for Coriolis meters: the measuring principle does not need a stabilized flow profile, so the piping can be laid out freely. Turbine, vortex and ultrasonic meters do require such runs.

The sensor can be mounted in any orientation. For viscous or fouling products, choose a self-draining arrangement so the tubes clear themselves. Project-specific guidance is provided at the design stage and is also described in the operating manual.

Testing to GOST R IEC 60068-2-6 covers three axes at 5–55 Hz and 0.35 mm amplitude. Where the line is pump-fed, the mounting arrangement and supports are additionally selected from actual flow parameters.

Interfaces: RS-485 Modbus RTU, a 4–20 mA output with HART, CAN, and a pulse channel rated 0–10,000 Hz; PROFIBUS PA is an option depending on execution. Data passed to the DCS and SIKN include flow, total, density, temperature and diagnostics.

Two Ex configurations exist. With ME100 the pair is marked Ex db ib IIC T6 Gb (transmitter) and Ex ib IIC T6…T1 Gb (sensor). ME200 switches to Ex db ia IIC T6 Gb and Ex ia IIC T6…T1 Ga. Dust protection is declared for ME200: Ex ia tb IIIC T80 °C Db.

Warranty: 18 months counted from delivery; if installation happens later, coverage is limited to 12 months from that date. The supply set carries the type description, TR CU conformity certificates, verification methodology and operating manual.

Service stays in Russia: crews handle commissioning supervision, startup, service and verification at the customer's site. There is no need to ship the meter away, either for start-up or for its next verification.

The meter does not need scheduled servicing: there is nothing that moves or wears inside. Documented reserve: 100,000 hours of mean time between failures and 20 years of average service life.

A single meter or a whole skid: we assemble metering units from one line up to a full custody transfer system, with verification equipment where the project calls for it. Configuration and layout are agreed per project. ---