When the handwheel is rotated toward the open position the upper stem is moved away from the diaphragms allowing the spring to push the lower stem away from the seat.

当手轮象开启位置旋转时，上阀杆离开横膈膜，弹簧推动下阀杆离开阀座。

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The lower stem is physically pulled away from the seat instead of being lifted away by the spring.

下阀杆是被从阀座上物理地推开，而不是被弹簧举起来。

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A spring on the valve stem tends to hold the valve on its seat (closed). The lower end of the spring rests against the cylinder head.

气门杆上的弹簧使气门保持在气门座上(关闭状态)。弹簧的下端抵在气缸盖上。

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Even its current, diminished performance, repeated at the general election that has to be held by next spring, would give M5S about 80 of the seats in the 630-seat lower house Chamber of Deputies and, perhaps, the balance of power.

ECONOMIST: Italian politics: A waning star? | The