Patent ID: 7250131

Claim:
A method for hot hydrostatic pressing by means of working liquid which tends to become unstable within a transition time when in contact with a blank heated to a high working temperature and at a pressure lower than the liquid's stabilization pressure, wherein the pressing of the blank heated to said high working temperature is carried out by the working liquid at a working pressure not lower than said stabilization pressure, and the pressure of the working liquid is raised to said stabilization pressure during a time period after said contact that is shorter than said transition time, said method being carried out over a heated blank placed in a working chamber of a press filled with the working liquid, and comprising the step of providing conditions for reducing said time period, wherein said step includes: forming a forechamber adjacent to the working chamber and isolated therefrom; filling said forechamber with said working liquid; raising the pressure of the working liquid in the forechamber to such level that, after said contact has been established, a further raise of pressure to the stabilization pressure takes less time than the transition time; opening a passage for the working liquid from the forechamber to the working chamber.