Abstract: An inlet valve for an air drier between an inlet (35) from a compressor and an inlet bore (32) comprises an axially movable valve element (31), a spring (34) for biasing the valve element into a closing position against a seat (30'), and a valve element shoulder (31'), on which the pressure in the inlet is arranged to act in a valve opening direction. A sealing on the shoulder is in the form of a U-sealing (36) allowing air under pressure admitted to the underside of the valve element for urging the latter in a valve closing direction to pass by the sealing to the inlet but preventing flow in the opposite direction.