Abstract: Disclosed is an adjustable valve for use with filters wherein internal valve partition members effect the relative duration and timing of withdrawal of the atmospheric and vacuum portion of filtrate from the filter. The valve further provides for the distribution of filtrate to clear or cloudy sump wells depending on the concentration of particulate matter contained in the filtrate portions. Timing and apportioning of the filtrate is accomplished by a combination timing plate and valve housing containing movable valve partitions, the valve body being in communication with a vacuum box and atmospheric drains.