Tipo e características da válvula de plug-in
Válvula de have a simple structure, quick switching, low fluid resistance, and fast angular stroke operation. In emergencies or other urgent situations, they can quickly connect or disconnect pipelines. Compared to gate valves and globe valves, they offer more flexible operation and faster switching. Plug valves use a plug with a through-hole as the opening and closing element. As the plug rotates with the valve stem, it performs the opening and closing actions. Small, unfilled plug valves are also known as "Cock" valves. The plugs of plug valves are mostly conical (although cylindrical plugs also exist) and form a sealing pair with the conical hole surface of the valve body.
Soft-Seated Plug Valves
Soft-seated plug valves are commonly used in harsh environments with corrosive, toxic, or highly hazardous media, as well as in applications where strict leak prevention is required and where valve materials will not contaminate the media. The valve body can be made of carbon steel, alloy steel, or stainless steel, depending on the working medium. Self-lubricating materials such as F4, F46, PVDF, PP, PO, and PE can be used for the valve seats and seals, ensuring good lubrication, low friction coefficients during the entire operation, flexible plug movement, and long service life. The design of the valve body inlet and outlet ports and the double-groove seal ring structure allow for the sealing pair to gradually change the sealing pressure during rotation until sufficient sealing pressure is reached when fully open or fully closed, achieving zero leakage. The double-groove seal ring not only ensures the stability of the liner in the valve body without displacement but also absorbs the slight deformation caused by temperature changes, while generating strong friction between the liner and the plug, thereby automatically cleaning the sealing surface and improving its lifespan. The unique design of the top of the piston, featuring a reverse lip seal, uses a combination of a soft seal membrane, a metal membrane, and adjustment gaskets to adjust the sealing pressure between the sealing surfaces, ensuring flexible plug rotation and sealing at the inlet, outlet, and middle flange connection ends. It is suitable for high-abrasion gas-solid and liquid-solid phase media, such as in PVC, urea, acetic anhydride, caustic soda production units, or media with high external leakage requirements, such as HF and phosgene. The media can flow bidirectionally, and the installation direction is unrestricted, allowing for online maintenance and greater convenience of use. The unique design prevents static electricity, ensuring safety against fire hazards.
Oil-Lubricated Hard-Seated Plug Valves
Oil-lubricated hard-seated plug valves can be divided into conventional oil-lubricated plug valves and pressure-balanced plug valves. Specially formulated grease is injected from the top of the plug into the tapered hole in the valve body, forming an oil film to reduce the valve's opening and closing torque, improve its sealing performance, and extend its service life. They can withstand working pressures of up to 64 MPa, operating temperatures of up to 325 degrees Celsius, and maximum diameters of up to 600 mm.
Conventional Oil-Lubricated Plug Valves
Pressure-Balanced Plug Valves
Hard-Seated Rising Stem Plug Valves
Handwheel-Operated Rising Stem Plug Valves: The working principle is as follows: When raised, the plug and the valve are fully open. When closing, rotate the handwheel to turn the plug 90 degrees to the closed position, then turn the handwheel of the transmission mechanism to lower the plug to achieve sealing. As the plug separates from the valve seat during valve opening or closing, the operation is very light, and the sealing surface is less prone to abrasion, resulting in a long service life. However, the handwheel driving torque is small, so the nominal size of the valve is usually not large. Handwheel-operated rising stem plug valves have a compact structure, small size, and low fluid resistance.
Three-Way and Four-Way Plug Valves
Soft-Seated Plug Valves
Soft-seated plug valves are commonly used in harsh environments with corrosive, toxic, or highly hazardous media, as well as in applications where strict leak prevention is required and where valve materials will not contaminate the media. The valve body can be made of carbon steel, alloy steel, or stainless steel, depending on the working medium. Self-lubricating materials such as F4, F46, PVDF, PP, PO, and PE can be used for the valve seats and seals, ensuring good lubrication, low friction coefficients during the entire operation, flexible plug movement, and long service life. The design of the valve body inlet and outlet ports and the double-groove seal ring structure allow for the sealing pair to gradually change the sealing pressure during rotation until sufficient sealing pressure is reached when fully open or fully closed, achieving zero leakage. The double-groove seal ring not only ensures the stability of the liner in the valve body without displacement but also absorbs the slight deformation caused by temperature changes, while generating strong friction between the liner and the plug, thereby automatically cleaning the sealing surface and improving its lifespan. The unique design of the top of the piston, featuring a reverse lip seal, uses a combination of a soft seal membrane, a metal membrane, and adjustment gaskets to adjust the sealing pressure between the sealing surfaces, ensuring flexible plug rotation and sealing at the inlet, outlet, and middle flange connection ends. It is suitable for high-abrasion gas-solid and liquid-solid phase media, such as in PVC, urea, acetic anhydride, caustic soda production units, or media with high external leakage requirements, such as HF and phosgene. The media can flow bidirectionally, and the installation direction is unrestricted, allowing for online maintenance and greater convenience of use. The unique design prevents static electricity, ensuring safety against fire hazards.
Oil-Lubricated Hard-Seated Plug Valves
Oil-lubricated hard-seated plug valves can be divided into conventional oil-lubricated plug valves and pressure-balanced plug valves. Specially formulated grease is injected from the top of the plug into the tapered hole in the valve body, forming an oil film to reduce the valve's opening and closing torque, improve its sealing performance, and extend its service life. They can withstand working pressures of up to 64 MPa, operating temperatures of up to 325 degrees Celsius, and maximum diameters of up to 600 mm.
Conventional Oil-Lubricated Plug Valves
Pressure-Balanced Plug Valves
Hard-Seated Rising Stem Plug Valves
Handwheel-Operated Rising Stem Plug Valves: The working principle is as follows: When raised, the plug and the valve are fully open. When closing, rotate the handwheel to turn the plug 90 degrees to the closed position, then turn the handwheel of the transmission mechanism to lower the plug to achieve sealing. As the plug separates from the valve seat during valve opening or closing, the operation is very light, and the sealing surface is less prone to abrasion, resulting in a long service life. However, the handwheel driving torque is small, so the nominal size of the valve is usually not large. Handwheel-operated rising stem plug valves have a compact structure, small size, and low fluid resistance.
Three-Way and Four-Way Plug Valves
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