Some important concepts
When dealing with DRA's a couple of concepts are important. The so called DRA-effect is a pipeline performance term and describes how much the drag (or pipe friction) in the pipeline drops when DRA is introduced to the system. Correspondingly, Increase of the Throughput tells how much more flow the pipe system can handle after injection of DRA. Both these terms are relative terms and are expressed in percentages based on initial conditions.
Naturally when using these terms, one must specify the concentration of DRA in the system. DRA concentration in the pipeline is normally used to express the amount of the DRA product injected into the pipeline.
One must be careful with this, since there is always a carrier system involved. The DRA is a very high molecular Wight polymer and it is in a solid form. A carrier system is needed to make the DRA suitable to injection hardware. The DRA Polymer concentration tells how much active polymer is contained in the product. If one wants to overlook the different carrier system, he uses the polymer concentration to define the concentration.