flow area orifice in the main flow line of the valve the land 70 is positioned so that in the high flow rate position of the sleeve 24 illustrated in fig2 it is sufficiently far from land 53 to provide unrestricted flow of supply air and in the reset position of the sleeve illustrated in fig5 it covers valve land 53 in operation the nut 57 is adjusted by rotation to axialy shift the sleeve 24 to provide the desired flow area at recess 72 this flow rate is controlled by varying the area of the orifice defined by the recess 72 and sleeve land 69 by moving the sleeve 24 to the position illustrated in fig2 land 69 on the sleeve uncovers the recess 72 sufficiently to provide unrestricted flow and hence the maximum flow rate for the valve 10 under normal operation air flows from inlet fitting 18 into valve body bore 25 out the valve body through radial bores 48 between the valve body 20 and the sleeve 24 in recess 67 into the radial passages 49 through open valve 22 and out fitting 19 flow rate is reduced by rotating nut 57 in a direction to shift sleeve 24 to the right partly or completely closing recess 72 flow rate is reduced to its minimum value by adjusting the sleeve 24 to the fig3 position where sleeve land 69 partly covers body land 52 there is a slight clearance between land 69 and land 52 in this position that meters the minimum flow through the valve if downstream pressure drops as a result of an empty material container interrupted material supply.