Abstract: A high-performance, robust gas-compression device of long-term reliability is adapted in particular for storing nitrogen gas under compression, and includes a substantially cylindrical body (1), a piston (4) partially projecting into the gas-storage chamber (2), upper (7) and lower (6) piston guiding sleeves surrounding the piston, a lubrication chamber (9) formed in one of the guiding sleeves, adapted for holding a lubrication fluid for lubricating the guiding sleeves, and respective annular sealing joints (14, 19) which are accomodated in the guiding sleeves. One annular sealing joint is formed with an annular groove in communication with the principal gas-storage chamber, thereby exposing that sealing joint to a pressure prevailing in the principal gas-storage chamber; the other sealing joint is exposed to a constant pressure from the lubricating fluid.

Abstract: An automatic-locking damping unit designed to prevent damage to pipelines exposed to violent shaking. The unit is characterized by the presence of a compensating chamber provided in the inner cavity of the cross-head; this chamber communicating with the inner space of the unit via two valves and nozzles. The invention is of interest to designers of hydraulic equipment.