Found under the following brands:
Annovi Reverberi-AR, Westward, Bostitch, Black & Decker, Craftsman, Devilbiss Air Power, DeWalt, Emglo, Excell, Porter Cable, Speedaire
Broken valve causing slow pump up or no compression at all. Replace this valve plate kit to restore compression (make sure piston and cylinder are not worn as well).
NOTE: The D30139 Gasket Kit must be ordered if you are replacing the N017592SV Valve Plate Assy.