The invention relates to a pipe breakage safety valve with an internal servo-valve (1) having a piston (4) which in one position on a control edge (6) blocks the connection between two internal pressure unions (2, 3) of the servo-valve. At an axial distance from said control edge, the valve piston has another control edge (8) which fluidtightly separates from the pressure unions a preloading spring (5) of the valve piston or a spring chamber (9) containing said spring.