Manual knife gate valve products in use and its models: From the 80's into our country. In less than two decades, its scope of use has expanded from ordinary areas to broader industries. Coal preparation, drainage and slag discharge from mine power plants. The city's sewage treatment was developed from the general industrial pipeline to the specialized pipeline systems such as food, health, and medicine. The ultra-thin knife gate valve completely solves the large flow resistance of ordinary gate valves, flat gate valves, ball valves, globe valves, regulating valves, and butterfly valves due to its small size, small flow resistance, light weight, easy installation, and easy disassembly. , heavy weight, difficult installation, large area and other difficult problems. After the knife gate valve appeared, a large number of universal cut-off valves and regulating valves had been replaced. Until now, the United States and Japan have used large amounts of global gate valves.
Precautions and characteristics of the use of manual knife gate valves: The gate of the knife gate valve is a gate plate, the direction of movement of the gate plate is perpendicular to the direction of the fluid, and the knife gate valve can only be fully opened and fully closed, and cannot be adjusted. And throttling. The gate has two sealing surfaces. The two sealing surfaces of the most commonly used mode gate valves form wedges, and the wedge angle varies with the valve parameters, usually 50. The gate of the wedge-type gate valve can be made into a whole, called Rigid gate; can also be made to produce a slight deformation of the gate, in order to improve its craft, to make up for the deviation of the sealing surface angle in the process of processing, this type of gate is called the elastic gate blade type gate valve closed, the sealing surface Can only rely on the medium pressure to seal, that is, rely on the pressure of the media to press the sealing surface of the gate to the valve seat on the other side to ensure the sealing of the sealing surface. This is self-sealing. Most of the knife-type gate valves are forced to seal, ie When the valve is closed, it is necessary to force the gate plate to press against the valve seat by external force to ensure the sealing of the sealing surface.
Work performance and installation:
Manual knife gate valve has the advantages of simple and compact structure, reasonable design, light material, reliable sealing, light and flexible operation, small volume, smooth channel, small flow resistance, light weight, easy installation, and easy disassembly. It can work at 1.0MPa. -2.5MPa, working temperature -29-650 °C normal work. The knife gate valve has a shearing function, which can scrape off the sticky material on the sealing surface and automatically remove the debris. The stainless steel gate plate can prevent the sealing leakage caused by corrosion. This type of valve should generally be installed horizontally in the pipeline.
Manual knife gate valve installation and use:
1.Before installation, check the inside of the valve chamber and the sealing surface, and do not allow any dirt or sand particles to adhere;
2. The bolts at each connecting point require uniform tightening;
3. Check that the packing area is pressed tightly to ensure that the packing is tight and that the gate plate is flexible;
4. Before the user installs the valve, the model of the valve must be calibrated, the connection size and the direction of the medium should be observed to ensure consistency with the valve requirements.
5. The user must reserve the necessary space for valve actuation when installing the valve.
6. The wiring of the driving device must be carried out according to the wiring diagram;
7. The knife-type gate valve must be maintained regularly and must not be crushed and squeezed freely so as not to affect the seal.