1,138,166. Rotary compressors. AQUACHEM Inc. June 8, 1966 [Sept. 30, 1965], No. 25621/66. Heading F1F. A rotary compressor of the radially sliding vane kind which includes lubricant for lubricating the operating parts and sealing the vanes with respect to the compressor working chamber, includes in an end cover of the compressor 10, Fig. 1 an enlarged boss 56, having a bore 57 housing a lubricant filter cartride 72 held in position by a spring 74 and a cap 66 which may be removed to permit replacement of the cartridge. Lubricant from an external source passing through a transverse part 22 in the boss and the cartridge 72 passes through passages 60, 62, 64, (63), (67), Fig. 2 (not shown) to lubricate the bearings and also into the compressor inlet passage 65 to be mixed with the incoming air to seal the vane ends. The passage 65 is fitted with an adjustable throttling plug 106 and a non-return valve (not shown) which prevents the back flow of air and lubricant into the compressor inlet when the compressor is not working.