Flow switches when the float passes up in front of the switch the switch becomes open. (Break to alarm) Even if the float goes up beyond the level the switch remains open i.e. it latches off. Unless the float comes down and goes below the high level, the switch will not turn on. Thus the switch is Bi-stable with stable states.

Flow switches when the float passes up in front of the switch the switch becomes open. (Break to alarm) Even if the float goes up beyond the level the switch remains open i.e. it latches off. Unless the float comes down and goes below the high level, the switch will not turn on. Thus the switch is Bi-stable with stable states.