Valve block for a central tyre inflation system

A valve block 3 for a central tyre inflation system (CTIS) for a vehicle tyre T, the valve block comprising: a gallery 33; a first compressed air port 17 and a second compressed air port 13; at least one inlet valve VINC1, VINC2, the or each inlet valve being operable to open or close communication between the gallery and the first compressed air port; a control valve VINSS operable to open or close communication between the gallery and the second compressed air port, wherein the control valve has an orifice that is smaller than an orifice of the or each inlet valve; at least one exhaust valve E1, E2 operable to open or close communication between the gallery and an exhaust outlet 23; and at least one outlet valve VFL-RR operable to open or close communication between the gallery and a tyre supply line TSL for supplying compressed air to the vehicle tyre. By grouping the various valves into the valve block it is intended to provide a compact arrangement where the flow of compressed air is managed to minimise air use and to reduce the frequency with which the compressor is activated and deactivated.