Fluid resistance and installation direction of the valve: the flow resistance of the gate valve is smaller than that of the globe valve, the medium channel inside the valve body is straight, and the medium flows in a straight line. Compared with the globe valve, it is more labor-saving when opening and closing. The gate valve can be installed horizontally or vertically without changing the flow direction of the medium. The ball valve is generally installed horizontally; the globe valve can be used to change the direction of installation. The so-called dark valve is actually a dark stem valve, which corresponds to the open stem valve and is a classification of gate valves. The gate of the gate valve moves in a straight line with the valve stem, which is called an open stem gate valve, and the nut of the valve stem of some gate valves is set on the gate. So called dark stem valve.
