Tank truck manhole filter

摘要

A filter apparatus for use in filtering dust and the like from a pressurized air stream flowing through a manhole of a hopper trailer in a particulate transfer system includes a filter sheet having a shape substantially corresponding to the shape of the manhole and a plurality of filters mounted thereon. A retainer flange is installed in the manhole for supporting the filter sheet and a filter hold down is provided for holding the filter assembly in the manhole and for pressing the filter sheet into contact with the retainer flange. The filter hold down clamp contacts the filter sheet along the central longitudinal axis of the passage in order to provide one-point hold down of the sheet.