A rising stem valve comprising a valve body, a two part valve stem and a stem guide washer. The valve body has a valve seat in a passage between an inlet and outlet port. The two part valve stem comprising a rotating stem and a non-rotating stem and the rotating stem has a threaded bore receiving a threaded end of the non-rotating stem. The non-rotating stem has a non-circular cross section external of the threaded bore and is adapted to carry a closure head to the valve seat. The stem guide washer has a bore positioned in mating relationship with the noncircular cross section of the non-rotating stem, whereby the stem guide washer prevents the stem from rotating when the upper stem is rotated.