Auxiliary manual operation on a bistable multiway valve is achieved with
a valve member able to be reciprocated with the performance of a switching movement
and furthermore operating device extending athwart the direction of the switching
movement. There is a provision such that the operating device includes at least
two mutually parallel plungers, which on operation act on second different flanks
of the valve member, operation of one plunger locking the respectively other plunger.