Straight-Tube Coriolis Flow Meter

A straight-tube Coriolis flow meter measures mass flow on a single straight measuring tube driven into vibration, with no bend in the flow path. When fluid passes through the vibrating tube, the Coriolis force twists the tube ends in opposite directions and the twist amplitude is proportional to mass flow through a factory K-factor. Because the bore is full and straight, particles, fibers, and high-viscosity slurry pass without accumulating at a bend. The same tube reads density from the resonant-frequency shift and reads temperature from an embedded RTD. Pressure drop is the lowest in the Coriolis range, which makes the straight tube the right pick for slurry, drilling mud, paper-mill stock, and any service where U-tube and V-tube bends would trap solids or impose unacceptable head loss.

U-tube Coriolis has two parallel curved measuring pipes that join at a 180-degree bend. On clean liquid service the U-tube delivers the broadest accuracy range and the most mature design. On slurry service the bend becomes a particle trap; cement slurry settles in the elbow during a process stop, paper fiber laces around the bend during low-flow periods, and drilling mud sand accumulates against the curve inner wall. The straight-tube design removes the bend entirely. A single full-bore straight measuring tube means particles, fibers, and sand pass through with the bulk flow. Pressure drop is also the lowest in the Coriolis range, useful for high-flow service where U-tube head loss is undesirable. The trade-off is that the straight-tube design needs careful zero-point management because there is no twin-tube common-mode rejection on temperature drift; this is handled by the embedded RTD compensation and by zero correction at process temperature during commissioning.

Yes. The straight-tube full-bore geometry passes paper stock at 1 to 4 percent fiber consistency without lacing or pulp accumulation that fails U-tube installs. The thick-stock line from refiner discharge to headbox at a paper mill is a standard application. Accuracy on stock is ±0.5 % of rate (one grade below clean-liquid ±0.2 % because fiber changes effective density during a basis-weight transition), and the embedded density measurement is useful for tracking consistency online. For pulp-bearing food liquid (orange juice with pulp, tomato paste, fruit purée) the same straight-tube fits the process side; a separate sanitary-coriolis build with Triclamp connections handles the final-fill side where CIP and SIP cleanability matter.

Wear life on abrasive slurry depends on particle size, particle hardness, slurry velocity, and duty cycle; the factory does not publish a single MTBF number because the answer ranges by an order of magnitude across applications. For lime slurry, calcium hydroxide, and most water-based mud the 316L tube wall handles years of service without measurable wear. For sand-laden drilling mud or mining concentrate at 3 m/s or higher we recommend inspection of tube wall thickness every 6 months on the first year of service to build a wear curve specific to that service. For high-chloride slurry the titanium alloy build resists pitting; for acid slurry the Hastelloy C build handles sulfuric and oxidizing chemistry. Quote the tube-wall thickness to the application engineer with the slurry specification and a service-life estimate comes back with the engineering review.

Oil-well cementing pumps cement slurry at high pressure to the wellhead during primary cementing and remedial squeeze jobs. The build covers working pressure up to 35 MPa standard on the straight-tube build with ANSI 1500 LB or DIN PN160 flange ratings, which fits primary cementing across most onshore wells. For higher-pressure squeeze jobs above 35 MPa the high-pressure threaded Coriolis (separate model) extends the range to 100 MPa, and the application engineer routes the quote there based on the wellhead pressure data. Wetted parts on cementing service are typically Hastelloy C for sour-service slurry with H₂S exposure, or 316L for sweet-service cement. Accuracy ±0.2 % of rate is the standard pick for cementing-job billing where the operator pays on slurry mass pumped.

Standard lead time is 5 to 7 business days from order confirmation, factory direct. Each meter ships with an ISO 9001 calibration certificate listing the K-factor, the density coefficient pair, the calibrated DN, the tested flow range, and the zero-point stability value for that serial number. Hazardous-area certification is Ex d [ia] IIC T6 Gb (flameproof body with intrinsically-safe sensor connection) standard. IP67 ingress and EMC 2014/30/EU compliance ship standard. Calibration is on a gravimetric water rig at the factory; for slurry, paper-stock, and cementing builds the buyer can arrange witness calibration at a third-party flow lab before shipment when the application engineer flags a non-Newtonian density correction requirement.