How to distinguish open stem gate valve from closed stem gate valve

The stem nut of the rising stem gate valve (lifting stem gate valve) is located on the valve cover or bracket. When opening and closing the gate valve, the stem nut can be rotated to realize the lifting of the stem. The threaded part of the stem is not in contact with the medium, which is not easy to be corroded by the medium, and is conducive to lubrication of the threaded part of the stem.

The stem nut of the rising stem gate valve (lifting stem gate valve) is located on the valve cover or bracket. When opening and closing the gate valve, the stem nut can be rotated to realize the lifting of the stem. The threaded part of the stem is not in contact with the medium, which is not easy to be corroded by the medium, and is conducive to lubrication of the threaded part of the stem.

The stem nut of the dark stem gate valve (rotary stem gate valve) is in direct contact with the medium in the valve body. When opening and closing the gate valve, it is realized by rotating the stem. The advantages of dark stem gate valve are that the height of the gate valve is unchanged when opening and closing, the installation space is relatively small, suitable for large diameter valves and installation space is limited pipeline, such as underground pipeline, etc.. However, to show the open and close height of the dark stem gate valve, an open and close indicator should be installed to show the open and close height of the dark stem gate valve. Dark stem gate valve stem thread directly contact with the medium, easy to be corroded by the medium, and can not be lubricated, relatively easy to damage.