High pressure barrel

A high-pressure piston-cylinder assembly, comprising:

• a cylinder comprising a cylindrical chamber and two or more sections which are longitudinally stacked and joined to form the cylinder that surrounds circumferentially at least a portion of the cylindrical chamber;
• a piston configured for moving in and along a longitudinal axis of the cylinder;
• and
• a base configured for being coupled with the cylinder to provide mechanical support to the cylinder;
• wherein the piston comprises a piston sealing block at a lower end of the piston and a first sealing member configured to tightly encircle the piston sealing block for providing sealing function to the piston-cylinder assembly;
• wherein the base has a cylindrical sealing block protruded from the base and a second sealing member configured to tightly encircle the cylindrical sealing block for providing sealing function to the piston-cylinder assembly;
• and
• wherein each of the sections includes one or more releasing channels extending radially from the longitudinal axis and along a radial direction through the cylinder for releasing of liquid or gas fluid generated during compaction treatment.