Abstract: A pumping apparatus, more especially for fluid materials containing entrained gas pockets, comprises a single entry centrifugal impeller pump and means for maintaining a reduced pressure on the side of the impeller opposite said single entry to the pump. The pump impeller may have gas evacuation passages extending through the impeller disc from orifices located on the low pressure side of the impeller blades. The pumping apparatus preferably includes a liquid chamber communicating with the pump casing on said opposite side of the impeller, means controlled by the liquid level in said chamber for connecting the latter either with a vacuum source or with atmosphere, and means responsive to atmospheric pressure within said chamber for discharging liquid therefrom to the inlet side of the centrifugal pump.

Abstract: A plastic container includes a one piece plastic body portion having a cylindrical outer wall and a bottom wall, and a one piece cap portion having a cylindrical outer wall and a top wall. The outer wall of the cap has a snap fit around a portion of the outer wall of the body to hold the cap on the body. The top wall and the bottom wall have a plurality of small holes therethrough which allow gases and vapors to enter the container but prevent the contents of the container from leaving the container. The holes are in the shape of square truncated pyramids with the larger area ends of the holes being at the inside surface of the respective walls. A label may be secured around the cylindrical outer surface of the container across the junction between the body and the cap to help prevent removal of the cap from the body.