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In many pulp applications, 8-19 % medium consistency is used to achieve cost savings or technical benefits in the process. The mediumconsistency pump, is basically a centrifugal pump with an open impeller. It acts as a turbulence generator fluidizing the pulp at the inlet. A normal head is up to 150 meters and pulp flow is controlled by means of a valve mounted directly on the pump discharge flange. There are two basic ways to run the pumps, as variable speed pumps or static head pumps. There is clear difference in how to use the medium consistency valves with these two pump styles. With a variable speed pump, it is important to run the pump with a fully 90 degree open valve. The valve will be throttled only when the pressuredifferential over the valve goes below the critical point that creates the danger of blocking the valve. This can happen only at very low pump speeds. The other case is the conventional method, whereby the static head of the pump is controlled by means of amedium consistency valve. In these cases the valve opening is typically limited to 70 degrees, to ensure that the pressure differential over the valve stays above critical level. Metso has created a specially designed V-port segment valve for this highly visible application. An extensive amount of testing has been conducted in cooperation with a leading pump manufacturer anda university. This research work has given us important knowledge of the flow behavior and clogging prevention in this demanding application. This specially designed V-port segment valve provides an optimized flow path for medium consistency pulp. The flow path in the valve is continuously increased to eliminate restrictions where material may build up. The outlet flange is one size bigger than the inlet to ensure this. Additionally, the body is equipped with a flushing connection. The flow path is V-contoured to be able to control small capacities without risk of dewatering.