open and shut valve

基本解释

Heart sounds is heart throb process in , shut by the valve inside the heart , open , and the sound that the oscillatory place such as systole or diastole produces.
心音是心脏搏动过程中，由心脏内瓣膜关闭、开放、以及收缩或舒张等振动所产生的声音。
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Many pressure dominated testing valve is through pumping of relieving annulus pressure to realize open or shut down hole test valve and keep annulus pressure for certain all the time.
许多种压控测试阀均是通过环空加泵压打开，泄掉泵压关闭，开井过程中环空始终保持一定的开启压力。
Butterfly valve is closed parts ( valve flap or disc for disc ), around the valve axis of rotation to achieve the open and close a valve, in the pipeline mainly as shut off and throttling effect.
蝶阀是指关闭件（阀瓣或蝶板）为圆盘，围绕阀轴旋转来达到开启与关闭的一种阀，在管道上主要起切断和节流作用。