Case
Case
When the inverted seal gate valve is fully open, there is a sealing structure at the connection between the valve disc and the valve stem and inside the valve stem and valve cover (i.e., the bottom of the stuffing box). When fully open, the two contact and squeeze together to form a seal. Function, reduce the internal pressure erosion of the packing in the stuffing box, extend the service life of the packing, and reduce the possibility of external leakage. Generally, gate valves and globe valves have inverted sealing requirements.
The gate valve is one of the most commonly used valves to cut off the flow of media. Its sealing element is a valve plate, so the gate valve is also called a gate valve. Most gate valves are mandatory sealing valves, that is, when closing the valve, pressure must be applied to the valve plate. When the gate valve is fully open, the flow channel is straight and the valve plate is almost not washed by the medium.
The inverted seal gate valve is equipped with an inverted sealing device. After the valve is fully opened, an inverted seal is formed, and the packing can be replaced under normal operation of the system.
①The structure is simpler than that of elastic gate valve;
②At higher temperatures, the sealing performance is not as good as the elastic gate valve or double gate valve;
③Suitable for high-temperature media that are prone to coking.
It is a special form of wedge single gate. Compared with the wedge gate valve, it has good sealing performance at high temperatures, and the gate is not easily stuck after being heated; it is suitable for steam, high-temperature oil, oil and gas and other media, and is suitable for parts with frequent switches. Not suitable for media that is prone to coking.
①The sealing performance is better than that of the wedge gate valve. If the inclination angle of the sealing surface and the valve seat are not very accurate, it still has good sealing performance;
②After the gate sealing surface is worn, the metal pad at the bottom of the spherical top center can be replaced with a thicker one. Generally, there is no need to surfacing and grinding the sealing surface, which is difficult to achieve with a single gate or elastic gate.
③There are more parts than other types of gate valves;
④In addition to being suitable for steam, oil and other media, it is also suitable for parts with frequent opening and closing and media with greater wear on the sealing surface. It is not suitable for media that are prone to coking.
①The sealing performance is worse than other forms of gate valves;
②Suitable for media with lower temperature and pressure;
③Except for the gates with fixed plates on the two gates that are not easy to fall off, any gates that are fixed with lead wires are easy to fall off and are unreliable in use.
④The processing and maintenance of the sealing surfaces of the gate plate and valve seat are simpler than other forms of gate valves.
The flat gate valve is a member of the gate valve family. Like the wedge gate valve, its main function is to control the opening and closing of the pipeline, rather than regulating the medium flow in the pipeline. Its advantages are small fluid resistance, labor-saving opening and closing, short structural length, and unrestricted flow direction of pipeline media.
The disadvantage is that the sealing pair has two sealing surfaces, which requires complex processing and high cost. It is taller than other valves and takes a long time to open and close. The relative friction between the sealing surfaces during opening and closing can easily cause scratches.
①The valve seat adopts a shaped sealing ring seal and a floating valve seat structure that applies preload force, so that the valve inlet and outlet are sealed in both directions, and the opening and closing torque of this structure is only that of ordinary valves, making it easy to open and close the valve.
②The valve seat is inlaid with or overlayed with stainless steel (or cobalt-chromium-tungsten alloy) on the sealing surface, which has double sealing of metal and metal-to-metal. The sealing surface can also remove dirt from the gate plate.
③For metal-to-metal sealing valves, the outside of the valve body is equipped with a grease injection structure. The grease enters the valve sealing surface through the grease injector and the valve seat, making the valve achieve zero leakage.
④The gate plate of the valve with a diversion hole always matches the sealing surface whether it is fully open or fully closed. The sealing surface is protected from direct erosion by the medium, thereby extending the service life.
⑤When the valve is fully open, the channel is smooth and straight, the flow resistance coefficient is extremely small, there is no pressure loss, and the pipeline can be cleaned through the hair ball.
⑥This valve adopts a packing structure with self-sealing ability, which does not require frequent adjustment. It is extremely light to open and close, and the sealing performance is reliable. The stuffing box is equipped with an auxiliary sealing grease injection structure, and the sealing performance is absolutely reliable, truly achieving zero leakage and solving the problem. This eliminates the problem that the general valve packing is most prone to leakage.
⑦When the valve is closed, it can automatically remove the high pressure in the inner cavity to ensure safe use.
⑧Fully enclosed structure, good protective performance, adaptable to all-weather requirements.
⑨The valve is equipped with an indicator rod or observation window to indicate the opening and closing of the valve.
