A safety-valve, in which a weight is employed. Here a is the valve, b b the boiler, c c the valve-seat, usually, like the valve itself, made of gunmetal, d the lever turning upon a fixed center at e, and pressing upon the valve by a steel point f, a guide for the lever g a weight which may be shifted backwards and forwards according to the pressure desired.

Lever Safety-valve

A safety-valve, in which a weight is employed. Here a is the valve, b b the boiler, c c the valve-seat,…

A form of spring safety-valve, in which a series of bent springs h h h are placed alternately in opposite directions, their extremities sliding upon the rod i, and the springs being kept down by the crossbar k; a being the valve, c the valve-seat, and b b part of the boiler.

Lever Spring Safety-valve

A form of spring safety-valve, in which a series of bent springs h h h are placed alternately in opposite…