What is a Knife Gate Valve
What is a Knife Gate Valve
How does the Knife Gate Valve work
Knife gate valves use thin metal plates to isolate flow in pipes, channels, or pipes. This metal plate is called a "knife" blade which is manually driven by a hand wheel, or automatically driven by a cylinder or gear motor. For manually operated knife gate valves, the hand wheel is connected to the screw and the other end of the screw is connected to the knife. Turning the handwheel moves the tool up and down the thread of the spindle, gradually changing its position from open to closed and vice versa. When fully opened, the knife is completely unaffected by fluid, and when closed, the knife edge is fixed between the two seals to prevent leakage. For automatic tool valves, the actuator is connected to the tool shaft. For example, in a pneumatic valve, a piston connected to the tool brake replaces the screw, and compressed air drives the piston and ram up or down to close or open the valve.
Knife gate valves are different from other types of valves
Knife gate valves are very similar to standard gate valves. The main difference is that knife gate valves use thinner gate plates, sometimes with real knife edges around them. It is suitable for fluids with high viscosity or containing a large number of solid particles, such as mud, wastewater or paper pulp. As with gate valves, standard knife-edge gate valves are used for on-off flow control, not flow control.
What is knife gate valve used for
Knife gate valves are primarily used to open/close fluids for process control or to isolate downstream equipment for maintenance activities. It is not usually used in flow control applications, but special flow control variants are available, especially for low pressure and low speed applications. These valves feature a robust design, position control and improved sealing.
When to use knife gate valve?
Knife gate valves are ideal for applications where positive closing/opening is required for high solid content or high viscosity liquids. These applications are ideal for knife gate valves because the knife can cut through the material to seal properly. Some standard gate valve designs force material into the seal seat, preventing the valve from closing and sealing completely. This is why knife gate valves are the first choice for such difficult applications.
What are the types of knife gate valves?
1.Electric knife gate valve
Electric knife gate valve simply refers to any knife gate valve operated with an electric actuator. These valves are ideal for automatic operation requirements, but have no access to compressed air. A common form of electric actuator is the gear motor.
