Plug valve, also known as rotary globe valve, is a type of valve used to cut off or regulate fluid flow. Its main features are simple structure, easy operation, and good sealing performance,widely used in industries such as petroleum, chemical, metallurgy, and power, this article will provide a detailed introduction to the working principle, classification, and application fields of plug valves.
Working principle of plug valve：
A plug valve is mainly composed of valve body, valve cover, valve stem, plug, and sealing components. When the valve is closed, the plug is tightly attached to the valve stem to prevent fluid from passing through;When the valve is opened, the plug disengages from the valve stem, allowing fluid to flow smoothly. The structural forms of plug valves include cylindrical plug valves, conical plug valves, and spherical plug valves.
Classification of plug valves
1. Classified by structural form
(1) Cylindrical plug valve: The valve body is cylindrical, and the plug is linearly related to the valve stem, suitable for low and medium pressure applications.
(2) Conical plug valve: The valve body is conical, and the plug is in a conical relationship with the valve stem, suitable for high-pressure and high-temperature applications.
(3) Spherical plug valve: The valve body is spherical, and the plug is in a spherical relationship with the valve stem, suitable for high-pressure, high-temperature, and high-speed applications.
2. Divided by working methods
(1) Fully closed plug valve: When the valve is completely closed, the plug is tightly attached to the valve stem, preventing fluid from passing through; When the valve is fully opened, the plug disengages from the valve stem, allowing fluid to flow smoothly.
(2) Half closed plug valve: When the valve is half closed, the plug is tightly attached to the valve stem, preventing fluid from passing through; When the valve is halfway open, the plug disengages from the valve stem, allowing the fluid to flow smoothly.
3. Divided by connection method
(1) Flange connected plug valve: The valve is connected to the pipeline through a flange connector, which has good sealing performance and easy installation.
(2) Threaded connection plug valve: The valve is connected to the pipeline through a threaded connector, which has the characteristic of easy disassembly. Application fields of plug valves.
Plug valves have been widely used in industries such as petroleum, chemical, metallurgical, and power. The following are some typical application areas:
1. Petroleum industry: Plug valves are mainly used in oil wells, refineries, oil field pipelines, and other occasions to cut off or regulate oil flow.
2. Chemical industry: Plug valves are used for the transportation pipelines of chemical raw materials and products, as well as for the import and export control of equipment such as reaction vessels and distillation towers.
3. Metallurgical industry: Plug valves are used for water and gas supply systems in hot rolling and cold drawing steel plants, as well as for controlling furnace emissions.
4. Power industry: Plug valves are used for steam transmission, cooling water supply and other systems in power plants, as well as for the protection and control of busbar systems in substations.
As an important industrial valve, plug valves play an important role in various industries due to their simple structure, good sealing performance, and wide range of applications. With the development of technology and the continuous improvement of demand, plug valves will be applied and developed in more fields.
