Oval Gear Flowmeter Working and Installation Guide

Working principle of Oval Gear Flowmeter:
What you see below is the oval gear flow meter which has oval-shaped rotors, each with gears on it that spin inside a spherical housing. Differential pressure from fluid in the tube causes the gears to rotate and empty fluid out into the stream.

A rotating shaft is measured by contactless sensors as it passes them. Every tooth on the shaft generates a pulse, and this increases the measurement resolution. This results in an exact measurement of even the smallest volumes. The measurement unit contains two pick-offs that are offset by half a tooth’s width to generate a frequency proportional to flow rate. Basically, the measurement accuracy increases with increasing viscosity of the medium.

 

How to install Oval Gear Flowmeter? 

Strainer:

You must install Filters into a pipe to ensure safe, uniform flow of clear, homogeneous substances. Filters with meshes that strain out particles smaller than 80 microns are typically used. A section of the pipe is left empty and flushed with water before a meter is installed in order to rid it of particles  and debris. If the strainer is not cleaned regularly, the flow meter will not function properly.

AIR PURGE / LINE PRESSURE

Always take care of reverse flow, it should be eliminated so the pipe line is designed accordingly. To avoid damaging the meter, isolation valves are installed in the pipe lines to allow the rest of the piping system to be drained while the new section is connected. Pressure needs to be avoided in this step, so slow fluid movement into the pipe line is recommended due to air bubbles that would damage the meter if they were to enter it. Avoiding cavitation helps limit pipe damage in this step.

REED SWITCH

Oval gear flow sensors work by using low differential pressure across their bodies to turn two oval gears. If you see below configuration, the rotation can be too slow to accurately detect anything, so they can only be used in low-speed counting applications. Another issue you might face is that they can produce inaccurate rates at high speeds, so they must be utilized in low-speed applications only. However, the performance improves with increasing viscosity. You may use this configuration to achieve accuracy of 0.1% of the reading at 1000 cP (Centipoise) and higher; above this viscosity the gears must be specially profiled to improve accuracy.

Techno Control Corporation are assisting industries by providing the right flowmeter according to their media and output expectations. We are dealing in flowmeters in Pakistan