What Are the Knife Gate Valves? (2)
The knife gate valve with its sharp knife-shaped disc is used for liquids and gases with high density, and it was mainly applied to the paper industry at the very beginning. That is, this kind of gate valve is ideal for cutting off pulp. It is cheap, it is convenient to be operated;it is used for blocking the media such as sludge and slurry. As a result, the knife gate valve is quickly expanded into other fields. However, when the valve is used for dry bulk, its utility is greatly diminished.
With the seal element around the disc, liquids can go through the knife gate valve’s disc instead of clinging to the disc, whereas when the knife gate valve is used for the media such as powder, the media will cling to the elastomer seal and abrade the sealing surface, degrading the sealing performance of the knife gate valve.
Features of knife gate valves
The knife gate valve has great shearing action because of its knife-shaped disc, and it is suitable for fluids such as fibers that are difficult to control, which make the knife gate valve widely applied to industries of paper, foods, petrochemicals, etc.
The rising sealing surface of the disc can remove the debris clinging to the sealing surface. That is, the debris will be removed by the knife-shaped disc automatically.
The knife gate valve has dual functions, that is, the function of cutting off the flow and throttling the flow.
The knife gate valve occupies small working space, and it can effectively reinforce the pipe to reduce the vibration.
The knife gate valve with the triangle bracket can save the raw material and guarantee the required mechanical property.
The knife gate valve is suitable for various piping arrangements and can be installed at any angle.
Instructions of knife gate valves
Before installation, it is necessary to check the valve cavity and the sealing surface of the knife gate and there should not be debris and sands.
It is necessary to maintain the knife gate valve regularly. Furthermore, the knife gate valve should not be collided or pressed so as to avoid the sealing performance.
The knife gate valve’s connecting bolts are supposed to be tightened evenly.
The stuffing box of the knife gate valve is required to be pressed tightly to ensure the sealing performance and the disc’s being opened and closed flexibly.
Before installation, the user must check the size, and the connection dimension of the knife gate valve. Furthermore, the flow direction of the media should be in accordance with the operating requirements of the knife gate valve.
When the user installs the knife gate valve, enough working space should be reserved for the valve actuator.
The connection of the knife gate valve’s actuator should be based on the wiring diagram.
Source: China Knife Gate Valve Manufacturer – Yaang Pipe Industry (www.ugsteelmill.com)