When the closed channel, the wedge-shaped head with a stem to open up the ball and pressed to seal the valve seat.

当关闭通道时，用阀杆的楔形头使球体涨开与阀座压紧达到密封。

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Ball is a sphere with a circular channel for gate parts, ball rotation with the stem of the valve action to achieve headstock.

球阀原理，球阀是用带有圆形通道的球体作启闭件，球体随阀杆转动实现启闭动作的阀门。

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Full bore pipeline ball valves the channel diameter and the same diameter, only a small fluid resistance, but also easy to clean pipes.

全通径球阀的通道内径与管线内径一致，不但流体阻力小，也便于管道清理。

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First Simon Davies earned a corner as he burst after a ball down the right channel, then Earnshaw slalomed in from the left to blast a shot off Per Mertesacker's shins.

BBC: Wales 0-2 Germany

But Cardiff made the game safe with a third goal on 73 minutes, Joe Ledley's pass across the left channel allowing Parry to strike the ball through Evans' legs into the net.

BBC: Chasetown 1-3 Cardiff

Physically overwhelmed by their fast and imposing opponents, Greece essentially collapsed its entire team into the defensive third of the field, allowing the Germans to knock the ball around in the middle of the pitch and wait for an open channel to clear.

WSJ: Euro 2012: Germany Kicks Greece Out of Euro (Soccer Tournament)