Piston pump

A piston pump, particularly a high pressure piston pump for aggressive and/or abrasive and sometimes hot flow media, comprising means forming a suction valve and a pressure valve;

• means forming a valve through-chamber extending between said suction valve and said pressure valve for passing a flow medium, said valve through chamber having an open end portion, an axis and axially spaced upper and lower ends;
• means forming a working chamber which is separate from said valve through-chamber and accommodates a displaceable piston;
• means forming a force-transmitting chamber which partly surrounds said valve through-chamber and communicates with said open end portion and with said working chamber wherein said force transmitting chamber accommodates a force-transmitting medium which transmits energy of displacement of said piston to the flow medium and separates the flow medium from said piston essentially without entering the valve through-chamber so as to perform exclusively force-transmitting functions, said valve through-chamber and said force-transmitting chamber being formed as parts of a common chamber and located substantially concentrically to one another so that the exclusively force-transmitting medium in the force-transmitting chamber displaces concentrically outside of the flow medium in the valve through-chamber without intersection with the latter and wherein the working chamber of the piston being disposed at a vertical distance to the open end portion for preventing the flow medium to penetrate to the piston;
• a housing block forming said common chamber, said common chamber having a substantially circular cross section, a substantially vertical axis, upper and lower openings coaxial with said axis and leading to said suction valve and said pressure valve, a side opening located near said upper opening and leading to said working chamber;
• and a pipe coaxial with this axis and extending from said upper opening into said common chamber, said pipe having an open lower end arranged at a distance from said lower opening, said pipe subdividing said common chamber into said valve through chamber located inside said pipe and said force-transmitting chamber outwardly surrounding said pipe.