Publisher Summary The purpose of this chapter is twofold: first to describe the results of the use of a polymer slurry for the purpose of drag reduction in a hydraulic capsule pipeline and, second to review mechanisms that cause the degradation of polymeric drag reducing agents. The drag reducing agent used was poly (ethylene oxide) powder with a molecular weight of 4,000,000. These experimental tests were conducted in a 55 mm diameter, 24 meter long re-circulating hydraulic capsule pipeline with a 4 meter straight test section. The effects of the drag reducing agent were based on pressure gradient and flow rate measurements along the straight test section. Results indicate that a polymer slurry in hydraulic flow increases the polymer lifetime by a factor of two and throughput increases by 8 percent compared to hydraulic flow with dissolved polymer. In hydraulic capsule flow the effects are less pronounced, but still significant. Hypotheses and models in the literature point to possible explanations for the polymer's loss of effectiveness. Explanations are suggested for the polymer's loss of effectiveness based on hypotheses and models presented in the literature; namely, high shear stresses because of velocity gradients, moving mechanical devices, and changes in cross-sectional area. From a molecular perspective the chain length of the polymer has an effect on the level of degradation.