Abstract: A valve controlled by-pass stud mechanism for a structure defining a stud receptacle and having a bleed passage intersecting the stud receptacle and normally containing a pressurized fluid medium. An elongate stud body is positioned in sealed relation within the stud receptacle and has a vent passage and defines an internal valve seat located about the vent passage and also defines a valve receptacle having internal threads. A needle valve is in threaded engagement with the internal threads of the valve receptacle and is movable by its threaded engagement within the valve receptacle between a closed position in sealing engagement with the valve seat and blocking flow of pressurized fluid from the bleed passage to the vent passage and an open position spaced from the valve seat and permitting flow of pressurized fluid from the bleed passage to the vent passage.