Abstract: The invention relates to a device for filtering a fluid, especially a liquefied plastic, said device comprising a housing, a supply channel, a discharge channel and optionally backwash channels. At least two filter elements are arranged in corresponding filter regions in the flow path of the fluid, in a filter carrier which is mounted in such a way that in can be perpendicularly displaced in relation to the direction of flow, said filter elements being able to communication with the supply channel and the discharge channel. Each filter region comprises two supply partial channels which are worked in to the filter carrier or the housing and are oriented away from the filter regions towards the discharge channel. Said discharge channel comprises housing partial channels which flow together to form the discharge channel.

Abstract: The invention relates to a feed pump for delivering fluid media, wherein the pump bearings are lubricated by the feed medium itself. Connecting channels with valve devices are provided on the suction side and on the pressure side upstream and downstream, respectively, of a displacement element and link the bearing area of the pump with the production channel. Said connecting channels are configured as straight bores in the pump housing. The valve devices are configured as tappets that are disposed in the associated connecting channel sections so as to be displaced while being tight with respect to suction.

Abstract: In a filter changing device with a flow path for the plastic in which one two or more filters can be inserted into the flow path as desired, the invention proposes to fit the filter support in such a way that it can assume a working back rinse and filter change position, in which, in the back rinse position, the plastic is caused to reverse its direction of flow through two interconnected flow channels without permitting air to penetrate into the filter changing device and in which there is free access to one of the filters in the filter changing positions. As the back rinse position can succeed a filter changing position, it is possible to clear the whole filter changing device of occluded air before a plastic processing plant starts production.