进口闸阀按阀杆构造的分类和结构特点
Construct a gate valve by the valve stem 1) rising stem gate valve: the valve stem nut on the valve cover or bracket opening and closing the gate, with a rotating valve stem nut to stem the rise and fall. This structure is beneficial to the valve stem lubrication obvious degree of opening and closing, so widely used. 2) rising stem gate valve: direct contact with the stem nut in the valve body, and media. Opening and closing gate with a rotating stem. The advantage of this structure are: gate valve height remains unchanged, so the installation space, applicable to large diameter gate valve or restricted installation space. Such a structure should be equipped to open and close indicator to indicate the opening and closing degree. The disadvantage of this structure are: the stem threads not only can not be lubricated, but also directly accept the medium erosion, and easily damaged.