Corrosion products formed by these reactions can prevent normal valve operation and can become embedded in the elastomeric stem tip, preventing the valve from making a complete seal.

这些反应产生的腐蚀产物会阻止正常的阀门运转，深入到人造橡胶阀杆顶端，造成阀门不能完全密封。

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The same force tends to reduce the seal on the pressure side with the result that bonnet cavity and the valve stem packing are nearly always subjected to maximum pipeline pressure.

而压力侧以相同的力削弱了密封，这样使阀盖腔室和阀杆填料几乎总是承受最大管道压力。

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The stem seal of a feed water control valve uses expanded graphite packing in order to produce friction and to economize on energy for the control valve working.

电站锅炉给水调节阀的阀杆密封采用柔性石墨填料，既降低了摩擦力，又为调节阀的运行节约了能源。

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