Using a flow conditioner ensures that both measurement accuracy and repeatability is maximized. Utilizing a properly designed perforated plate flow conditioner improves the fundamental fluid dynamics of the pipe flow itself. This creates a fully developed flow that is free of swirl, distortions, or any other flow asymmetry.
When a flow conditioner is utilized, the flow profile distortions are largely eliminated and fully developed flow is restored. This state of fully developed flow also utilizes wall friction and fluid viscosity to help determine the final shape of the flow profile. The wall drag that a fluid experiences shapes the flow profile, pulling it into a rounded, symmetrical shape and causing the flow to eliminate distortions.
Without the use of a flow conditioner, it can require as much as 100 to 300 pipe diameters in length to eliminate swirl and restore a fully developed flow profile in a pipe. These lengths are far too long to be used realistically. Flow conditioners are designed to accelerate the development of a fully developed flow profile. What normally takes hundreds of diameters, a properly engineered flow conditioner can accomplish as little as 3 to 5 pipe diameters. The results of this effect are: (1) flow profile distortions are largely eliminated, (2) flow profile symmetry is restored, and (3) swirl is reduced by up to 90-95%. This creates an ideal state of flow and also creates ideal conditions for measurement accuracy and repeatability.
A properly designed flow conditioner does not create an artificial or temporary flow profile in the pipe; rather, it helps create the correct flow profile for the fluid Reynolds number. The state of fully developed flow is assisted by both the wall friction and the viscosity for the particular fluid application. The fluid wall drag actually helps tune the flow profile. This is what pulls the fluid profile into the rounded, symmetrical shape and causes the flow to eliminate distortions. This profile will remain stable as the flow moves further and further downstream, resulting in the flow meter seeing the same flow profile independent of the installation location.
This constant flow profile is fundamental to flow meter repeatability. When a flow conditioner is installed in front of the meter, this ensures that the meter will always see the same flow profile, whether the meter is installed in the lab or in the field. With this repeatability ensured, it is easy to set up the meter for accuracy by using either an established flow measurement standard or a calibration facility, thus allowing the meter baseline to be set.
Canada Pipeline Accessories (CPA) recommends the use of flow conditioners in any fluid measurement scenario. If flow needs to be measured, a flow conditioner should be employed. Decades of testing and use have proven that high performance flow conditioners are an effective and efficient method of improving measurement accuracy of fluid flow.
CPA offers flow conditioners that have been extensively evaluated by independent laboratories and are the most effective and simple solution for any of your flow conditioning needs. They have been proven to provide stable performance downstream of even the most demanding installations, thus ensuring worry-free measurement. Our experts are ready to discuss how each flow conditioner can enhance measurement repeatability and accuracy. Call us today 403-236-4480 to speak to one of our team experts about your flow conditioning needs.
