is a simple solution although this is not illustrated explicitly in fig1 whereby the valve slide 1 has within the annular chambers 15 16 a plurality of radial projections which for the purpose of guiding the valve slide 1 radially within the axial bore of the valve sleeve 3 project as far as the surface area of the latter the projections being spaced apart in the circumferential direction from one another and in the axial direction from the peripheral webs 17 delimiting the annular chambers 15 16 in such a way that the hydraulic through flow is not impaired in contrast to the cited prior art in which the peripheral edges on the valve slide cooperate with radial through flow bores in the housing the partially hollow piston shank of the valve slide 1 now requires only one radial through flow bore 9 which cooperates with the low pressure control edge 5 extending peripherally on the valve sleeve 3 in order in the depicted pressure breakdown position of the valve slide 1 first position to effect pressure equalization between the working connection a and the low pressure connection t via the hollow piston shank while at the same time in the depicted pressure breakdown position of the valve slide 1 the high pressure control edge 6 is concealed by the surface area of the valve slide 1 with the result that the high pressure connection p is separated from the working connection a the radial.