Abstract: A boltless bonnet assembly is provided for use with a valve, particularly a gate valve having a valve body comprising an upper housing, a lower fluid passageway, a gate, and a valve stem having a thrust washer. The bonnet assembly has a bonnet with a lower plate adapted to sealingly engage an underside of a lip of the upper housing, the lip defining an opening in the upper housing, and a cylindrical neck having inner and outer sets of threads at an upper portion. A bonnet clamp or alternatively a lock ring and clamp ring are provided to engage the outer threads of the bonnet to clamp the plate tightly against the underside of the lip, and a bonnet cover is provided for retaining the thrust collar of the valve stem in a recess in the bonnet, the bonnet cover being threaded into the set of inner threads of the bonnet.