Abstract: A filtration unit comprising a filtration media sub-unit secured in an outer frame. The sub-unit comprises a fibrous filtration media enclosed in an inner frame having an upstream frame element and a downstream frame element. Each frame element has longitudinal and transverse struts and the intersections of these struts are in a single plane on the side of the frame elements which contact the filtration media. In one embodiment the filtration unit is enclosed in a sock of knit fabric; in another embodiment, there is a piece of knit fabric between the outer frame and the downstream frame element of the inner frame. The longitudinal struts may have portions which are perpendicular to and project beyond the principal plane of the periphery of the downstream frame element. If such perpendicularly projecting portions are provided, they are preferably arcuate in configuration.

Abstract: Peristaltic pump including a housing having a backing plate and an upstanding arcuate wall, a pump shaft mounted in the backing plate, and a rotatable pump head mounted on the shaft and comprising at least one roller means for squeezing a segment of flexible tubing against the arcuate wall to achieve pumping of a liquid through the tubing. The pump head includes a pivotable handle having a recessed portion which cooperates with a ledge in the pump shaft to prevent the pump head from moving upwardly from the shaft when the pump is in operation. Also included are means comprising a roller bearing and clutch assembly for preventing rotation of the pump head in an incorrect or undesired direction during manual operation.