High pressure device for fluid media

A cylinder unit of a high pressure pump for a fluid comprising:

• a cylinder formed by at least two concentric tubular components coupled by a shrink connection;
• at least one connection surface between the at least two concentric tubular components has grooves;
• a flange part with a sealing system being detachably connected on one side of the cylinder, the sealing system having a plunger movable back and forth and a bearing bushing;
• the bearing bushing being pressed against the flange part by a disk spring coupled to a radially outermost component of the at least two concentric tubular components;
• the disk spring having a distal portion supported on the radially outermost component and a proximal portion supported on a part of the bearing bushing;
• and
• a valve body connected to bear against an other side of the cylinder,
• wherein the at least two concentric tubular components have a welded metallic connection to each other in a region of the valve body.