Next, let’s talk about some important considerations for the installation, operation, and maintenance of pneumatic knife gate valves.

Release time:

2023-05-11

Pneumatic knife gate valves have a wide range of applications, spanning from ordinary fields to more diverse industries—from coal preparation, gangue removal, and slag discharge in coal-fired power plants to urban wastewater treatment; from general industrial pipelines to pipeline systems used in food, sanitation, and pharmaceutical industries. So, what are the key considerations when installing, using, and maintaining pneumatic knife gate valves?

　　Some precautions for the installation, use, and maintenance of pneumatic knife gate valves.

　　1. Installation: Before installing the pneumatic knife gate valve, inspect the valve cavity and sealing surfaces to ensure there is no dirt or sand adhering to them. All bolts at connection points should be tightened evenly. Check that the packing is properly compressed—this ensures both a tight seal and smooth operation of the gate. Before installing the valve, the user must verify the valve model, confirm the correct connection dimensions, and pay attention to the flow direction of the medium to ensure compliance with the valve’s specifications. When installing the valve, users should leave sufficient space for the valve actuator. The wiring of the actuator must be carried out according to the circuit diagram.

　　2. Usage instructions: The pneumatic knife gate valve requires regular maintenance and must not be subjected to random impacts or compressions, as this could compromise its sealing performance.

　　3. Maintenance and Care: The handwheel, handle, and actuator mechanism must not be used for lifting purposes and are strictly prohibited from being subjected to impacts. Double-disc gate valves should be installed vertically (i.e., with the valve stem in a vertical position and the handwheel at the top). Gate valves equipped with bypass valves should have their bypass valves opened prior to opening the main valve (to balance the pressure difference between the inlet and outlet and reduce the opening force). Gate valves fitted with actuators should be installed according to the manufacturer’s instructions. If the valve is frequently opened and closed, it should be lubricated at least once a month.

　　How does a pneumatic knife gate valve achieve a sealing effect?

　　A knife gate valve has two sealing surfaces. In the commonly used wedge-type gate valve, these two sealing surfaces are wedge-shaped; the wedge angle is adjusted according to the valve’s specifications to optimize the sealing performance, typically set at 50 degrees. Alternatively, the sealing surfaces can be designed with a slight flexibility to enhance manufacturability and compensate for any deviations in the sealing surface angles during machining. Such valves are referred to as flexible-seal gates. When an pneumatic knife gate valve is closed, the sealing surfaces are sealed solely by the pressure of the medium—specifically, the sealing surface of the gate is pressed against the valve seat on the opposite side by the medium’s pressure, thereby ensuring reliable sealing performance.

　　The corrosion resistance of knife gate valves in acidic environments depends on the materials used in their manufacture. The corrosion resistance of a knife gate valve material refers to its ability to withstand damage caused by exposure to air, water, acids, salts, or other chemical environments. Corrosion resistance is particularly important; in addition to employing various coatings or coating technologies, a more fundamental approach is to enhance the performance of the steel itself.

　　That’s all for today’s explanation of “Some Precautions for the Installation, Use, and Maintenance of Pneumatic Knife Gate Valves.” Does everyone understand? I hope the information shared above has been helpful to you. Thank you for watching, and we’ll see you again in the next episode.

The vast majority of stainless steel knife gate valves employ forced sealing: that is, when the valve is closed, an external force is applied to forcibly press the gate against the high-pressure valve seat, thereby ensuring a tight seal on the sealing surfaces. Some gates can also be designed to undergo slight deformation, which helps improve their manufacturability and compensate for any misalignment in the sealing surface angles that may occur during the manufacturing process. Such gates are referred to as flexible gates. The majority of knife gate valves rely on forced sealing—meaning that when the valve is closed, an external force is used to press the gate firmly against the high-pressure valve seat, thus guaranteeing a secure seal on the sealing surfaces. Valves of this type are generally installed horizontally in pipelines.

2023-05-11

Next, let’s talk about several operating procedures for knife gate valves.

When a gate valve is closed, the sealing surfaces rely solely on the pressure of the medium to achieve a seal—specifically, the sealing surface of the gate is pressed against the valve seat on the opposite side by the medium’s pressure, thereby ensuring a tight seal. This type of sealing is known as self-sealing. In contrast, most gate valves employ forced sealing: when the valve is closed, an external force must be applied to press the gate against the valve seat in order to guarantee the sealing performance of the sealing surfaces. Such valves should be installed vertically in the pipeline.

2023-05-11

Next, let’s talk about whether knife gate valves have fire-resistant and anti-static requirements.

When an electrostatic knife gate valve is opened or closed, the sphere and the valve seat experience mutual friction. The static electricity generated by this friction tends to accumulate on the sphere—something that is unacceptable for ball valves used in gas, fuel, and chemical pipelines, as it could potentially lead to pipeline explosions. Ball valves with antistatic designs are equipped with static discharge devices.

2023-05-11

Next, let’s talk about some important considerations for the installation, operation, and maintenance of pneumatic knife gate valves.

2023-05-11

Slurry Valve Manufacturer: How are stainless steel knife gate valves good?

Slurry valve manufacturer: How to improve the compliance rate and productivity of stainless steel gate valves and prevent a large number of maintenance tasks—this is Skafu Valve’s top priority. The stainless steel gate plate effectively prevents sealing leaks caused by corrosion. The stainless steel gate plate effectively prevents sealing leaks caused by corrosion. Features: This valve boasts advantages such as simple and compact structure, reasonable design, lightweight and material-saving, reliable sealing, easy and flexible operation, small size, smooth flow passage, low fluid density, light weight, ease of installation, and ease of disassembly.