TOP OPERATED TANK CAR LADING VALVE ALSO OPERABLE FROM THE BOTTOM

摘要

ABSTRACT OF THE DISCLOSUREIn a top operated tank car valve, a mounting flange is welded toan opening in the bottom of the tank. A valve seat is located inboard of,and above the lower surface of, the mounting flange. A vertically extend-ing cage is integrally attached to the mounting flange. A top operator ex-tends to the top of the tank, and a stem is attached to the lower portionof the top operator. The stem extends into an opening in a valve closureplug. A non-round cavity is formed in the bottom of the stem. The closureplug includes a seat which engages the valve seat located within the mount-ing flange. The closure plug includes a circular guide ring which engagesa portion of the vertically extending cage as the closure plug moves betweenopen and closed positions. The closure plug includes a vertical, generallycentral opening which communicates with the circular head portion of thevalve stem. A retainer, held in place with retainer fasteners extendingfrom the bottom of the retainer into the closure plug, holds in place aseal located in a circumferential groove in the closure plug. The retainerincludes an extension which extends through the vertical, generally centralopening in the closure plug. The retainer fasteners can be removed from thebottom of the car, providing access to the non-round cavity in the valvestem. Thus, the closure plug may be opened from the bottom of the tank witha tool extending through the vertical center opening. Since the valve seatis located within the mounting flange which does not extend more than one(1) inch below the tank bottom, a tank car skid is not needed to comply withAAR regulations concerning projections from the bottom of railwaytank cars.