How do oval gear flow meters work?

by Hei White Heiwhite

With a wide array of design options and enhancements, Industrial Flow Meters offer highly accurate, durable and cost effective flow measurement solutions today. Positive displacement Oval Gear Flow Meter technology has provided designers and flow meter market leaders with decades of proven flow measurement advantages since the early 1960s. The purpose of this article is to assist specifies, plant engineers and end users in understanding the advantages and limitations of oval gear flow meters.

Measuring Positive Displacement Oval Gears

In the measuring principle, two high precision toothed oval gears (rotors) are driven by media flow and mesh with each other. As the flow increases, the rotational speed of the rotors increases. Whenever there is flow, precisely defined volumes of fluid are swept through the meter. Rotor gear rotations are a measure of the amount of fluid that has passed through the meter - each rotation is detected by a sensor, and volume is calculated using a conversion factor ( K factor ). Positive displacement flow meters offer direct measurement of volumetric flow rate, which is a key distinction.

Suitability of the fluid

In Oval Gear Flow Meters, solids may wedge between oval gears. Solids, if any, should be soluble and low in concentration.

Before using a mechanical flow meter, good engineering practice always recommends upstream filtration. It is important to minimize or eliminate air within the liquid stream upstream of the Oval Gear Flow Meter. Your supplier will be able to recommend the right size particulate in line strainers. This flow technology does not work with gases.

Oval Gear Flow Meters are well suited to a wide variety of fluid types, including water.

Be sure to work with an experienced, high quality oval gear manufacturer who can review all details of your flow application when reviewing flow range and meter size considerations.

Advantages of oval gear flow meters

A Positive Displacement Oval Gear Flow Meter provides a number of key advantages - the right manufacturer can provide:

Reading accuracy

Repeatability is excellent

Maintenance is minimal

It is suitable for a variety of fluids, including water and high viscous fluids

Installation is easy. No flow conditioning is required

Turndown ratios that are exceptional

Viscosity does not affect accuracy

With pulse or mechanical registers, no power is required

Heavy Duty Robust Design for Industrial Use

Optional outputs include pulse, 4-20mA, intrinsically safe, and explosion-proof

The following industries are typical:

OEM process fluid manufacturers have embraced Oval Gear Flow technologies because they offer very small footprints, no flow conditioning, and high accuracy and repeatability with very attractive volume unit pricing.

The manufacture of fuel products and fuel additives requires highly accurate and repeatable blend and batch flow measurements suitable for harsh plant and mobile environments.

With and without temperature compensation capability, fuel supply and return meters are highly accurate in the Fuel Measurement, Consumption and Monitoring market. Engine, generator and pump feed loops need to be measured and collected precisely for mining, marine, boiler, fracking and other high fuel consumption clients.

In summary:

The oval gear flow meter is ideal for clean process fluids and can be used in a wide range of media applications. The absence of flow conditioning allows for greater design flexibility. Meter accuracy is not affected by changing viscosities or maintenance. Compared to other flow technologies, Oval Gear Meters offer a very attractive cost of ownership while providing highly accurate and repeatable results. Oval Gear Meters are mechanical meters and should not be used in fluids containing non-soluble particles. Gases are not suitable for this meter. Water applications should always be reviewed by a qualified oval gear flowmeter manufacturer.

You can count on Macnaught USA for all your Americas Macnaught Oval Gear Flow Meter needs.

Our company makes only Oval Gear Flow Meter instrument technology, and we have done so since 1964. We are the largest oval gear flowmeter manufacturer in the world.

For USA, Canada, Mexico, Central America, South America, and the Caribbean, Macnaught USA can process Flow Meter quotes within an hour with supporting documentation.

Materials used for construction include aluminum, stainless steel, and PPS.

Options for pulse / 4-20mA / intrinsic safety / explosion proof output

With an integral display, you can choose from Display with Pulse and 4-20mA output, or Display with Rate & Total only.

We offer remote flow computers with advanced logic and communication protocols.

All flow meters are tested with an individual calibration certificate along with the K-Factor. We carry a large inventory of stocked meters in sizes 14" -4" with flow ranges from .13 to 317 gallons per minute.