US 56826195 A description fig1 schematically shows a steam turbine fuel valve generally designated 10 contained in a valve cabinet 12 the valve comprises an inlet opening 14 and outlet opening not shown to open and close the inlet opening a valve shaft 16 extends in one direction through a cylindrical stuffing box 18 and through the valve to the inlet opening the valve shaft extends in the other direction out of the valve to an actuator not shown the actuator translates the valve shaft longitudinally to open and close the inlet opening the valve shaft is allowed to translate longitudinally through the contents i e the packing assembly of the stuffing box which act to seal the valve from atmosphere preventing the escape of fuel from the valve the preferred embodiment of the valve packing assembly contained in the stuffing box is shown in an exploded format in fig2 to seal the valve shaft a compression member 20 is placed over the valve shaft and slid over the shaft into the stuffing box the compression member preferably a coiled spring with an aperture sized to receive the valve shaft engages an upper wall 22 fig1 of the stuffing box a set of three packing rings 24 26 28 is placed over the shaft and slid into the stuffing box up against the compression member in the preferred embodiment shown all three rings are generally v shaped as shown in fig3 and 4 this v shaped ring is commonly referred to as a chevron shaped ring a cross section of the v shape is generally triangular with a central triangular opening 40 and a crown 38 the crown 38 of the.