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。
2
The same force tends to reduce the seal on the pressure side with the result that bonnet cavity and the valvestem 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。
3
The stemseal 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.