Coriolis flow meters for cryogenic media

Electronics excite the oscillation of the sensor tubes, and the mass moving through them shifts the phase via the Coriolis force. That phase shift becomes mass flow directly, without an intermediate volume or density conversion.

Metering and dosing of liquid nitrogen, oxygen, argon and LNG across air separation plants, gasification lines, metallurgy, the food and electronics industries, medicine, cryogenic terminals and laboratories — the duties listed on this page.

It extends the working range to −196…+150 °C and adds parts built for extreme cold: cryogenic body and seal materials, thermal insulation and special cable entries. Standard executions are not rated for such temperatures.

Density and temperature of the cryogenic medium are measured simultaneously. This lets one instrument cover product quality and process parameters, without adding separate sensors to the loop.

The measurement is intended for single-phase cryogenic liquids; two-phase flow adds extra error. Also, below −150 °C most structural materials become brittle, so both the execution and the adjacent hardware are selected specifically.

Liquid nitrogen is the boundary duty for execution L: its −196 °C matches the rated limit, and LN₂ metering is covered during storage, transport and dosing in metallurgy, medicine and electronics.

Execution L handles liquid oxygen at −183 °C and liquid argon at −186 °C: metering at air separation units, gasification lines, in welding production and the electronics industry.

For low flows the entry size DN08..L with a U-type sensor is used: the larger oscillation amplitude keeps the signal stable even at minimal cryogenic flow. Such sets are common in laboratories.

Two-phase streams are a source of additional error, so the piping is arranged to present single-phase liquid to the sensor. The parameters of a specific duty are reviewed on request and the execution is selected accordingly.

Test rigs and laboratories are among the target duties of the line: high sensitivity at low flows and repeatable readings across cyclic runs are what cryogenic benches on liquid nitrogen and oxygen circuits require.

Before start-up the loop is cooled down gradually — this is cool-down, or pre-cooling; once at operating conditions the meter runs under thermal stabilisation. Gradual cool-down reduces thermal shocks and the risk of the liquid flashing; the 316L tubes undergo cryostabilisation, and the materials and seals are tested with cyclic temperature shocks.

Both geometries are available in execution L. The U-type covers the main range, from laboratory dosing to terminal flows; the Δ-type is more compact for tight skids but comes only in DN25.

The working range is −196 °C to +150 °C. It covers the common cryogenic liquids — LN₂, LO₂, LAr, LNG — and leaves margin for line cool-down at start-up; the limits are confirmed in the size tables.

Line sizes run from DN08 to DN80. The smallest serves laboratory dosing, the middle ones (DN25–DN50) process lines and transport, and DN80 handles large LNG flows up to 120 000 kg/h.

Tubes are made of austenitic 316L steel with low-temperature treatment, retaining impact toughness at −196 °C. Seals from PTFE and PEEK are rated across the full cryogenic range.

The jacket minimises heat ingress from ambient air, prevents frost on the body and stabilises measurement. Combined with vacuum insulation and inert-gas filling it protects the sensor from thermal shocks; it is ordered as option 19S.

ME100 is the base transmitter of the line, ME200 the extended one, with its Ex db ia IIC T6 Gb rating suited to cryogenic terminals and fuelling stations. For laboratory lines ME100 is sufficient.

The cryogenic execution is rated at ±0.5% on liquids, while the wider liquid meter family spans ±0.1% to ±1.0% by size. Calibration is individual, performed on a flow calibration rig before delivery.

Registration under No. 98506-26 opens operation within the sphere of state metrological regulation — the area that includes custody transfer and settlements between parties. The metrological documents are available on the site.

There are two routes: a flow calibration rig with reference meters, or on-site verification with provers, without removing the meter from the pipe. Both options are defined by the approved procedure. Provers — pipe and compact — can be ordered from the manufacturer.

It is the ratio of maximum to minimum flow within which the rated accuracy holds. In cryogenic service it matters for dosing: the feed varies from minimal to full rate, and accuracy is needed across the whole span.

A Coriolis sensor needs no straight runs — unlike turbine, vortex or ultrasonic meters. That simplifies the layout of a cryogenic bench or line, where every metre of pipe needs insulation.

The sensor is installed so that the liquid drains out and does not sit in stagnant zones; the drainable geometry matters at shutdowns and cool-downs. The exact piping arrangement is covered in the project recommendations.

Available outputs are 4–20 mA with HART, RS-485 Modbus RTU, CAN and a frequency/pulse output; PROFIBUS PA is an option depending on execution. Connection to DCS and laboratory data acquisition systems is a standard task.

The line covers hazardous areas in two steps. Base: ME100 — transmitter Ex db ib IIC T6 Gb, sensor Ex ib IIC T6…T1 Gb. Extended: ME200 — transmitter Ex db ia IIC T6 Gb, sensor Ex ia IIC T6…T1 Ga, dust option Ex ia tb IIIC T80 °C Db.

Confirmed to GOST R IEC 60068-2-6: 5–55 Hz, 0.35 mm displacement, three axes. On cryogenic sites packed with piping and machinery, vibration margin is a practical requirement rather than a formality.

Send a completed datasheet or use the online configurator: medium, flow range, pressure, temperature, connection and area classification. From those inputs execution L is configured to the required scope and a quotation is prepared.

Replacement is possible in many cases: when process and mounting dimensions match, no welding is needed. Meters already in service (including Micro Motion and Endress+Hauser) are checked against mounting dimensions and interfaces using a drawing or nameplate photo.

Box contents: operating manual, verification procedure, type description, certificates of TR CU conformity. The warranty ends at whichever is earlier — eighteen months starting at delivery, twelve months starting at installation.

Service work in Russia covers commissioning supervision, startup, servicing and verification. The cryogenic execution has no scheduled downtime for maintenance — no moving or wearing parts are used; the service life benchmark is 20 years. ---