Oval Gear Flow Meters

How Oval Gear Flow Meters Work

Oval gear flow meters are a type of positive displacement flow meter that utilizes oval-shaped gears to precisely measure the volumetric flow rate of a liquid. Let’s explore how it works:

The Core Components: The meter consists of two oval-shaped rotors that intermesh within a precisely machined housing.

The Trapping Mechanism: Fluid flowing through the meter pushes the oval gears to rotate. As the gears rotate, a specific volume of liquid gets trapped between the gear teeth and the housing wall. This trapped volume is known as a “pocket.”

The Measurement Principle: The continuous rotation of the gears constantly traps and releases precise pockets of fluid. By counting the number of rotations, the meter can determine the total volume of liquid that has passed through.

The Sealing Mechanism: The specific design of the oval gears and the housing, along with the capillary action of the liquid itself, creates a tight seal that prevents any leakage between the pockets.

Pulse Output for Measurement: Often, magnets are embedded within the rotors. As the rotors rotate, the magnets pass by a sensor, generating a pulse for each pocket of fluid that passes through the meter. This pulse output is then used to calculate the flow rate.

OVAL Gear Flow Meter Advantages

  • Traditional proven flow technology
  • Simple to install
  • No straight pipe runs required so flow meters can be installed in restricted areas

OVAL Gear Flow Meter Limitations

  • Not suitable for steam or multi-phase fluids
  • Fluid slippage adversely affects accuracy; this varies with flow rate, differential pressure, temperature, viscosity and clearance
  • Not recommended for low-viscosity fluids, including water or water-like fluids (because of an increase in fluid slippage)
  • Accuracy adversely affected by bubbles present in fluids
  • The oval gear flow meter is designed primarily for use with higher-viscosity fluids, which has led to applications such as the flow metering of oils, syrups and fuels.

Need Advice About Oval Gear Flow Meters?

iCenta is a instrumentation and control solution specialist with experience in control technologies for diverse applications, fluid types and process conditions. Call iCenta now for advice, sales & technical information on 01722 439 880.