Flow Measurement

Oval Gear Flow Meters

Flow Measurement

Positive Displacement – OaP/OuaP

The OaP and OuaP Series oval gear flow meters manufactured by Metroval are dual-chamber positive displacement (DP) instruments designed for applications requiring high accuracy, robustness, and increased mechanical stability in continuous operations. Designed specifically to serve the petroleum, petrochemical, refineries, and mining industries, these instruments are the preferred choice for the accurate measurement of gross, intermediate, or final liquid products.

It stands out for its unique construction where the outer housing and the measuring chamber form distinct and isolated units. This design ensures that any deformations suffered by the housing (due to piping stresses or thermal variations) are not transmitted to the inner chamber, maintaining constant accuracy and immune to external working conditions.

For fluids requiring strict temperature control, the OuaP Series offers the same metrological performance by adding an external heating chamber (jacket) for circulation of steam or thermal oil.

Discover our advantages

Benefits

Exceptional and constant accuracy (Dual Chamber)

The dual-chamber design isolates the mechanical and thermal stress measurement element from the pipeline, ensuring accuracy of ±0.2% to ±0.5% and repeatability of ±0.05% over long operating periods.

Thermal Control for Critical Fluids (OuaP Series)

The outer heating jacket allows for accurate measurement of fluids that solidify or excessively increase viscosity at room temperature, such as asphalt and resins, while maintaining the required fluidity.

Durability and stability

The great differential of this line is its extreme durability and calibration stability, since the measuring chamber works isobarically compensated, eliminating wear and tear and the need for frequent periodic adjustments.

The OaP and OuaP series are manufactured in diameters from 25 mm to 250 mm (1″ to 10″), serving flow rates of up to 600 m³/h and supporting pressure classes of up to 2500#. The transmission of the movement of the gears is done via concentric magnetic coupling, ensuring perfect tightness and eliminating friction that could affect accuracy at low flow rates. The system is modular, allowing the installation of mechanical totalizers, pre-determiners, card printers or electronic pulse transmitters (AG19/20) for integration with PLCs and automation systems.

DIFFERENCES BETWEEN THE SERIES:

OaP Series (Standard Double Chamber): High-performance model for custody transfer and fiscal measurement of hydrocarbons and chemicals where mechanical stability is crucial.
OuaP Series (Double Heated Chamber): Version equipped with external chamber for heating by steam or thermal oil. Indispensable for fluids that require temperature maintenance to ensure pumpability and accuracy of measurement.

The main applications where this type of equipment is essential include:

Transfer of Custody of Petroleum and Derivatives: It has approval of INMETRO/Dimel model No. 164/2013, enabling its application in transfer of custody, fiscal measurement, pipelines, terminals and refineries, ensuring regulatory compliance, legal certainty and metrological reliability in commercial transactions.
Biofuel Measurement: Used in mills and distribution bases for accounting and fiscal control of production and sales.
High Pressure Chemical Industry: Measurement of reagents and end products in processes operating in high pressure classes (up to 2500#).
Measurement of Heated Fluids (OuaP Series): Flow control of asphalt, liquid sulfur and heavy resins in processes that require constant heating.