Servall Engineering Works [P] Ltd. Supplies Stock Preparation Pressure Screen. Servall Engineering Works [P] Ltd. Manufactures paper machinery up to 250 TPD capacities. Stock Preparation Pressure Screen improves sheet formation by deflocculating the stock when used prior to the head box. Stock Preparation Pressure Screen can be used at many places in the process and for each application. This machine is design and motor rating give higher screening efficiency and reduced fiber content in rejects at low specific energy consumption. It is aerodynamically designed rotor to provide back flushing.