Abstract: A press for the hydrostatic extrusion of metallic billets to form tubes and other profiles includes a hollow high pressure cylinder having a removable liner which forms the inner wall thereof and which encloses the internal pressure chamber. To protect the removable liner from fatigue breakdown, the inner wall of the liner is coated with a protective coating of an organic polymer and a metallic tube is located adjacent the protective coating and concentric therewith, between the protective coating and the internal pressure chamber.

Abstract: A press for hydrostatic extrusion includes a pressure chamber for enclosing a pressure medium which is formed of a high pressure cylinder, a pressure generating piston, a die and a die support and seals. The die support includes an exchangeable support ring which engages the end surface of the liner and bridges the gap between the liner and the die. A metallic sealing ring is arranged within the liner in engagement therewith, forming a gap between the inner surface of the sealing ring and the outer surface of the die or die support. The die support has a groove in its upper surface which contains a sealing member against which the edge of the metallic sealing ring engages. The lower outer corner of the metallic sealing ring is bevelled to form a space which communicates with the outside of the press.