| 摘要 |
PURPOSE: To provide a valve for a supercritical fluid extraction apparatus which is capable of handling high-temperature and high-pressure fluids, is long in service life and is inexpensive. CONSTITUTION: The supercritical fluid extraction apparatus has a movable extraction cartridge. This cartridge in operation has insignificant pressure difference between its inside and outside walls. The supercritical fluid extraction apparatus has a fraction collector for extraction solvents, an automatic sample exchanger and an automatic cartridge transfer mechanism. These elements provide completely automated extractions. To automatically perform extraction, valves for the fluids are automatically opened and closed in synchronism with the insertion and removal of the cartridges. These valves press a hard ball 1014 to a softer valve seat 1013 with a stem 1027 that does not rotate significantly under the control of a rotary motor.
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