An inflation valve (20) for a sealing cuff (10) on a tracheal tube (1) has a helical ceramic spring (40) that urges a valve seal (45, 87) against a valve seat (28, 128). The actuator (51) by which the seal (45, 87) is lifted from the seat to open the valve includes a spring latch mechanism (53). The latch mechanism has three spring fingers (56) that are held resiliently in compression in a recess (60) before the first actuation of the valve. When first used, the actuator is moved forwardly to open the valve so that the free ends of the spring fingers clear the end of the recess and deflect outwardly. When the actuator (51) is released to allow the valve to close, the spring fingers (56) engage a latch surface (63) so that the spring (40) is held in greater tension.