SEAL EXTERNAL PRESSURE CONTROLLER FOR HIGH TEMPERATURE/HIGH PRESSURE FATIGUE TESTER

摘要

PURPOSE:To simplify the construction of the equipment by operating a control valve depending on a difference between pressures inside and outside of a compensation bellows communicating to an autoclave provided in a pressure compensation chamber communicating to an hydraulic chamber. CONSTITUTION:The inside of a bellows 13 and the inside of a compensation bellows 18 are communicated to an autoclave 10 and the compensation bellows 18 is stretched by an internal pressure thereof 10 causing the piston of a control valve 22 to lower. The inside of a pressure compensation chamber 17 is communicated to a hydraulic pressure introduction inlet 25 through an air hole 27 so that a pressure fluid from a pump 31 is fed to the pressure compensation chamber 17, a hydraulic chamber 3 and cylinders 2 and 23. As a result, with the pressure in the pressure compensation chamber 17 becoming equal with the internal pressure of the compensation bellows 18, a piston 24 is lifted by a hydraulic pressure from an introduction inlet 29. When the two pressures are equal, to each other, the side of the pressure compensation chamber 17 and the side of the pump 31 are cut-off while a pressure fluid is returned to a tank 30 through a constant pressure valve 32. This makes it possible to maintain the both pressures equal between inside and outside of the bellows 13.