| 摘要 |
The purge valve assembly is designed for use with a constant pressure sample cylinder for purging of the cylinder prior to installation in the field for collection of spot and composite samples. The purge valve assembly can be installed in newly manufactured constant pressure sample cylinders or can be added as an after market item. The purge valve assembly consists of a retainer which compresses a sealing element into engagement with an end cap to prevent fluid from bypassing the retainer. A valve element is urged into engagement with the sealing element by a spring thus closing the valve and preventing the escape of any fluid from the sample cylinder. To open the valve a valve actuator is manually depressed thus dislodging the valve element from sealing engagement with the sealing member thus allowing fluid to be vented to atmosphere or purged. An alternative embodiment combines the valve element and valve activator into an integral element. In another embodiment two sealing elements are used instead of one.
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