Abstract: A safety valve comprises a valve seat and a spring-loaded first control piston that is axially moveable with respect to the valve seat. The valve seat and the first control piston each having a central channel for a branched-off portion of a transported pressure medium. The first control piston central channel has an annular surface that is in fluid communication with the pressure medium. A spring is supported at one axial end by a flange of the first control piston and at an opposite axial end by a switching element. When the pressure medium reaches a predetermined operating pressure, the switching element is moved axially, through the release of an arresting mechanism, to that side which faces away from the valve seat to relieve the fluid pressure.

Abstract: A maximum-pressure plunger plump has, coaxial with its longitudinal axis, a compression valve and a suction valve. It has a sleeve that floats on a plunger. The sleeve rests on the end facing the head of the pump on an inset. the inset is provided with a seat area for the body of the suction valve and with suction channels. The sleeve has a bushing. The suction valve is in a form of a disk. It has a spring-loaded annular body that rests on the valve-seat area that the suction channels open out of in the insert in the pump head.The plunger's bushing (9) extends to th eend of the sleeve (7) that faces the head (2) of the pump with its face against the insert (12) and in that a sealing sleeve (15) that overlaps the area or seam of impact between the insert and the sleeve is accommodated in the flow channel between the bushing and the insert.