Quick response hydraulic shock suppressor for piping systems

摘要

A double-acting hydraulic cylinder has a piston disposed therein for dividing the cylinder into first and second portions with a single piston rod extending from one end of the cylinder. Each end of the hydraulic cylinder is connected to a hydraulic reservoir that is hermetically sealed and pressurized through the unique use of a metal bellows which pressurizes the hydraulic fluid. A pressure-compensated, variable orifice control valve is disposed between each end of the hydraulic cylinder and the reservoir for limiting the rate of fluid flow from the cylinder to the reservoir to a substantially constant value independent of external loads applied to the piston rod. The variable orifice increases in size with cylinder depressurization and thereby provides for a rapid release of internal residual hydraulic pressures after high dynamic loads are experienced. When used as a shock suppressor for piping systems unrestricted pipe motion is permitted in response to movement caused by thermal expansion or contraction, and pipe motion is suppressed by limiting the velocity of the pipes relative to a supporting structure during shock and oscillating load conditions. A lock-up indicator is used to provide an indication of high resistance of the device due to a lock-up condition. Radiation resistant seals are utilized throughout the device to provide for long maintenance-free periods required for nuclear applications.