The metal diaphragms act as the seal at the top of the valve. The primary improvement in this generation of valves is the elimination of the spring used to open the valve.

金属横膈膜在阀门的顶部作为密封。这一代阀门的主要的改进是取消了用于开启阀门的弹簧。

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Primary electric circuit for control system of miller, which is used to machine delivery valves, need to be improved because of its complexity and difficulty in maintenance.

出油阀铣床原有的电气控制系统控制线路复杂、维修困难，需要改造。

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Valves feature as standard secondary metal-to-metal seal in the event of the primary seat being destroyed by fire.

作为标准配置，阀门具有第二个金属对金属密封，以防万一第一个密封被火毁坏。

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Integral reactor systems -- including the reactor vessel itself, six steam generators, five primary coolant pumps, 12 isolation valves and more -- were stored outside for up to 18 months, exposed to highly corrosive tropical sea air and weather.

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The primary culprit behind the explosion appears to be the blowout preventer, a two-story-tall stack of valves on the seafloor that was built by Cameron in 2001 and designed to guillotine shut an out-of-control well.

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