Characteristics and Applications of Slab Gate Valves
1. Applications
A slab gate valve is a member of the gate valve family. Its main function is to control the opening and closing of the pipeline, rather than regulating the medium flow in the pipeline.
2. Advantages and Disadvantages
- Small fluid resistance, easy opening and closing, short structural length and unrestricted flow direction of pipeline media
- The sealing pair has two sealing surfaces, which are complex and costly to process. Compared with other valves, a slab gate valve is taller, and its opening and closing time is longer. The relative friction between the sealing surfaces is easy to cause scratches during opening and closing.
3. Structural Features
- The valve seat adopts O-ring seals and floating valve seat structure with preload, so that the inlet and outlet of the valve are sealed in both directions. The opening and closing torque of this structure is small, and the valve can be opened and closed easily.
- The valve seat is inlaid or surfaced with stainless steel or cobalt-chromium-tungsten alloys on the sealing surface, which has double sealing of metal and metal-to-metal, and the dirt of the wedge can be removed at the same time.
- For the valve with metal to metal seal, there is a grease injection structure outside the valve body. The grease enters the sealing surface of the valve through the grease injector and valve seat, so that the valve can achieve the purpose of zero leakage.
- The wedge with diversion holes can prevent the sealing surface from the scouring of the medium and extend its service life, whether it is fully opened or fully closed, it will always coincide with the sealing surface.
- When the valve is fully open, the channel is smooth; the flow resistance coefficient is small, and there is no pressure loss. A ball top can be used to clean the pipeline.
- The valve adopts the packing structure with small friction coefficient and little leakage, which does not need to be adjusted frequently. It is very convenient to open and close the valve, and the sealing is reliable. The drawback of the leakage of the packing part is solved.
- When the valve is closed, it can automatically release the high pressure in the inner chamber to ensure safe use.
- A slab gate valve has fully enclosed structure, good protection and can adapt to requirements of all-weather conditions.
- The valve is equipped with an indicator rod or an observation window to indicate the opening and closing of the valve.
