| 发明名称 |
SAFETY PACK-OFF FOR WELLS |
| 摘要 |
A safety pack-off operable to seal off the annular spaces between concentric pipe strings in oil and gas wells automatically in response to excessive fluid flows upwardly through the annular spaces.
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| 申请公布号 |
US3703904(A) |
申请公布日期 |
1972.11.28 |
| 申请号 |
USD3703904 |
申请日期 |
1971.09.07 |
| 申请人 |
JOHN MCCLINTON |
发明人 |
JOHN MCCLINTON |
| 分类号 |
E21B33/12;E21B34/08;F16K17/34;(IPC1-7):F16K31/00 |
主分类号 |
E21B33/12 |
| 代理机构 |
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代理人 |
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| 地址 |
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