Pressure booster with double-seat valve

A pressure booster for fluids having a booster piston which is embodied as a differential piston and having a control piston unit, wherein the pressure booster is configured such that a low-pressure side of the booster piston can be alternately connected by the control piston unit via a cylinder line to a low-pressure feed line and an outlet line, and a high-pressure side of the booster piston can be alternately connected to a high-pressure load line and a low-pressure feed line, and the booster piston also interacts with the control piston unit by a control line in such a way that the pressure which acts in the control line determines the position of the control piston unit and the pressure acting on various end face sections of a second end face of the control piston unit, whereby a spring is omitted from acting on any of the various end face sections of the second end face of the control piston unit, wherein:

• the control piston unit comprises two reciprocating elements which are embodied as seat valves and each of which interacts with a separate valve seat and which are designed such that one of the elements intermittently seals off the low-pressure feed line, which is alternately connected to the low-pressure side of the booster piston, with respect to the cylinder line and the outlet line, and the other element intermittently seals off the outlet line, which is alternately connected to the low-pressure side of the booster piston, with respect to the cylinder line and the low-pressure feed line, such that a higher pressure acting on the seat valves is achieved resulting in a stronger pressing of the seat valves onto their corresponding valve seats;
• wherein one of the elements is formed as a piston and has a rod-like section for acting on the other element, which rod actuates the other element in order for the outlet line and the low-pressure feed line to communicate with the cylinder line, via an annular chamber, wherein the annular chamber is located between corresponding cylinder bores in which the two elements reciprocate and the external surface of the rod-like element and remains free of engagement with the piston-rod.