摘要 |
A valve includes a column having an outer end portion defining a threaded bore, an outer mediate portion defining a first receiving recess communicating with the threaded bore, an inner mediate portion defining a passage communicating with the first receiving recess, and an inner end portion extending outwardly from a valve body and defining a second receiving recess communicating with the passage, and a valve stem having a first end portion formed with an outer thread, and a second end portion extending through the passage and formed with an annular flange received in the second receiving recess. A sealing device includes a primary set packing received in the first receiving recess, a secondary seal received in the second receiving recess and urged on the annular flange, a gland nut formed with an outer thread fixedly engaged in the threaded bore, a first biasing member mounted between the primary set packing and the gland nut, a lock nut fixedly mounted on the outer thread of the valve stem, and a second biasing member mounted between the gland nut and the lock nut.
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