Flow control valve

Claim 1

An adjustable valve assembly comprising: a valve body having a substantially cylindrical element in threaded engagement with a tubular element, said cylindrical element being threadably shiftable to a preselected one of an infinite number of axial positions relative to said tubular element; an internal cavity formed in said valve body; a first bore having one end in fluid communication with said cavity and the other end in fluid communication with the exterior of said valve body; a valve seat mounted on said tubular element and having a hard, substantially flat working face formed thereon, said working face being in communication with said cavity; an elongate stem in threaded engagement with a stem bore formed in said cylindrical element and having a hard, substantially flat working face substantially opposite said seat working face, said stem working face being movable toward and away from said seat working face responsive to threadable shifting of said cylindrical element relative to said tubular element; a second bore extending into said seat from the working face thereof and having a substantially smaller diameter than the diameter of said seat working face; means coupled with said valve body for permitting a flow of fluid through said second bore, such a flow having a rate which varies in response to the relative positions of said working faces; means for preventing removal of said cylindrical element from said tubular element; means for fixing said stem in a preselected one of an infinite number of axial positions relative to said cylindrical element; and an annular shoulder formed on said cylindrical element for flushly abutting an opposing annular shoulder formed on said tubular element thereby placing said cylindrical element in a predetermined axial position relative to said tubular element when said shoulders abut one another.