Air valve assembly for hydraulic jack

An air valve assembly adapted for mounting in the air hole on the outer oil cylinder of a hydraulic jack, comprising:

• a polygonal valve block, said valve block comprising a threaded neck forwardly extended from a front side thereof adapted for threading into the air hole on the outer oil cylinder of a hydraulic jack, a longitudinal center through hole, and at least one air hole radially extended through the periphery thereof in communication between said longitudinal center through hole and the atmosphere;
• an air guide block mounted inside said longitudinal center through hole of said valve block adjacent to said threaded neck, said air guide block comprising a spiral groove around the periphery thereof in communication between two distal ends of said longitudinal center through hole of said valve block;
• a stop plate fixedly mounted inside said valve block below said at least one radial through hole of said valve block and spaced above said air guide block, said stop plate having a center round hole for the passing of flow means;
• and
• a felt element fixedly mounted inside said valve block and attached to said stop plate at a top side and aimed at said at least one radial through hole of said valve block to stop hydraulic oil from passing out of the center round hole of said stop plate and to let outside air pass from said at least one radial through hole of said valve block through the center round hole of said stop plate into the space inside of said valve block below said stop plate.