My invention relates to that class of balanced slide-valves in which the valve is practically relieved from the pressure of the steam, this pressure being sustained by a plate supported above the valve, but so nearly in contact with it that the space between them will not admit steam enough to affect the valve. Such plates are designated as “pressure” plates, and have been made in some instances adjustable, in order that they may be closed up to the valve as the faces of the valve and its seat become worn. Heretofore such adjustments have been affected by different mechanical devices, among which there was, in one instance, a spring to move the plate laterally or crosswise of the valve while the pressure of the steam held the plate down; and in other instances screws were used to move the plate in two directions, both in line with the movement of the valve, and to hold the plate in its adjusted position. All of these devices, however, are liable to objections well understood by engineers. It is the object of my invention to obviate these objections in a balanced slide-valve; and to this end my improvements consist in utilizing the pressure of the steam for giving motion to the pressure-plate down inclined supports and toward the valve; in employing supports inclined to the face of the valve at a steep angle, considerably exceeding the angle of repose of the metal, so that the pressure of the steam on the upper surface of the pressure-plate may be relied on for giving to it the above-described motion, and in employing an adjustable stop to prevent the pressure of the steam from forcing the pressure-plate into too close contact with the valve. In the accompanying drawings, which form part of this specification, Figure 1 is a transverse section through a steam-chest in which my improved balanced slide-valve is applied, the section being on the line _x x_ of Fig. 2, and Fig. 2 is a longitudinal section on the line _y y_ of Fig. 1. [Illustration] [Illustration]