A valve apparatus 1 for a pressure-actuated system has a pressure medium input 7 and a pressure medium output 22. A relay valve 8 controls the pressure medium input 7. A pressure-actuatable inlet valve 23 is arranged between the relay valve 8 and the pressure medium output 22. Each pressure medium output 22 includes a pressure-actuatable outlet valve 28 controlling a fluidic connection of the pressure medium output 22 to a purge 16 leading to atmosphere. At least one outlet valve 28 or inlet valve 23 is formed as a diaphragm valve and has a valve diaphragm 29 which lies on a valve seat 30 and opens against the pressure in a purge chamber 31. For each diaphragm valve, an electrically actuatable purge valve 33 controls a fluidic connection of the purge chamber 31 to a purge line controlling the relay valve 8.