Let me give you a detailed introduction to the functions of the plug valve.

Release time:

2022-04-06

The function of a slide valve is simple yet effective. A slide valve serves solely as an on-off switch and cannot provide quantitative material flow control. It is used primarily to isolate the material flow when other valves and equipment require short-term maintenance or replacement. Although its operation is straightforward, the slide valve is a reliable shut-off device with a simple structure, low failure rate, and ease of disassembly and maintenance. Its components can be replaced independently without affecting its overall performance. Due to its suitability for use under negative pressure, slide valves are often employed in conjunction with rotary feeders.

　　The function of a slide valve is simple yet essential. A slide valve serves solely as an on-off switch and cannot provide quantitative material flow control; it merely shuts off the material flow temporarily to allow other valves and equipment to undergo short-term maintenance or replacement. Although its operation is straightforward, the slide valve is a reliable shut-off device with a simple structure, low failure rate, and easy disassembly and maintenance. Its components can be replaced independently without affecting its overall performance. Due to its suitability for use under negative pressure, slide valves are often employed in conjunction with rotary feeders.

　　The standard type of slide valve is designed for use at ambient temperatures. For materials that are temperature-sensitive or corrosive, custom designs can be provided based on specific application requirements. However, slide valves should not be used in applications requiring tight sealing or as gas shut-off valves, as this would prevent the slide valve from performing its intended function—and such functionality was not originally included in our product design.

　　Slide valves can generally be categorized into four types: electric slide valves, electro-hydraulic slide valves, pneumatic slide valves, and manual slide valves. A typical slide valve consists of several components, including the valve body, valve disc, valve disc structure, screw-driven clamping mechanism, expansion joint, and valve disc travel-driving mechanism. The valve disc is composed of a through plate and a blind plate, and it controls the flow and shut-off of the medium.

　　The floating seat is welded to the corrugated expansion joint. The walking drive mechanism moves the valve plate assembly, enabling the seamless transition between through-hole and non-through-hole valve plates. The clamping drive mechanism, via chain transmission, simultaneously rotates the lead screw transmission device, causing the lead screw and nut to move the floating seat horizontally. This action presses the sealing surface of the floating seat against the O-ring on the valve plate, thereby achieving valve sealing.

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.

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?

2023-05-11

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