Globe valve characteristics and classification methods

Shut-off valve is closing valve (valve) moves along the centerline of the valve. Globe valve is mainly used in the pipeline cut off. Globe valve has the following advantages: 1. In the process of opening and closing the sealing surface of the friction than the gate valve, wear-resistant. 2. Open height is small. 3. Usually only one sealing surface, the manufacturing process is good, easy maintenance. The use of stop valve is more common, but due to the larger opening and closing torque, the structure of a longer length, the general nominal diameter are limited to DN ≤ 200mm below. Stop valve fluid resistance loss greater. Thus limiting the wider use of globe valves. There are many types of stop valves, according to the position of the stem on the thread can be divided: First, the threaded stem stop valve stem valve thread on the outside of the body. Its advantage is that the stem is not subject to erosion of the medium, easy to lubricate, this structure is more common. As shown in Figure 2-8. Second, the lower thread stem stop valve stem valve thread in the valve body. This structure stem thread direct contact with the media, vulnerable to erosion, and can not lubricate. This structure is used for small caliber and temperature is not high place. According to the direction of the cut-off valve channel can be divided into; Straight-through valve, angle valve and three-way globe valve, the latter two kinds of stop valve is usually to change the media flow and distribution media.