进口闸阀按阀杆构造的分类和结构特点
按阀杆的构造进口闸阀的分类 1) 明杆闸阀：阀杆螺母在阀盖或支架上，开闭闸板时，用旋转阀杆螺母来实现阀杆的升降。这种结构对阀杆的润滑有利，开闭程度明显，因此被广泛采用。 2) 暗杆闸阀：阀杆螺母在阀体内，与介质直接接触。开闭闸板时，用旋转阀杆来实现。这种结构的优点是：闸阀的高度总保持不变，因此安装空间小，适用于大口径或对安装空间受限制的闸阀。此种结构要装有开闭指示器，以指示开闭程度。这种结构的缺点是：阀杆螺纹不仅无法润滑，而且直接接受介质侵蚀，容易损坏。 美国威盾VTON品牌的进口闸阀的详细产品有：进口日标闸阀、进口美标波纹管闸阀、进口低温闸阀，进口气动刀闸阀，进口刀闸阀，进口美标闸阀，进口锻钢闸阀，进口软密封闸阀，进口保温闸阀，进口不锈钢闸阀。
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.