Viking’s 4924A Series™ Positive Displacement (PD) pumps offer safety, reliability and high efficiency in refrigeration ammonia recirculation applications. Safety is achieved through use of a double mechanical dynamic shaft seal located between bearings for minimum possible shaft run-out, with a pressurized barrier fluid system, and O-ring type static seals where components are joined. Reliability is provided by slow speed operation and low differential pressures, which maximize bearing and seal life. And efficiency is inherent in the PD Internal Gear pumping principle, compared to centrifugal pumps. Viking pumps can usually use at least one motor size smaller than these technologies.