What are the uses of a stainless steel knife gate valve?

Release time:

2023-01-04

The stainless steel knife gate valve is one type among many gate valves. Compared with conventional gate valve products, it has several distinctive features. For instance, its structure is simpler and its dimensions are smaller. It’s also very easy to install. Additionally, it boasts flexible operation and quick opening and closing. So, which media are suitable for stainless steel knife gate valves? Let’s take a closer look below.

Stainless Steel Knife Gate Valve It is one type among many gate valves. Compared with conventional gate valve products, it has several distinctive features. For example, its structure is simpler and its dimensions are smaller than those of ordinary gate valves. It’s extremely easy to install. Additionally, it boasts flexible operation and quick opening and closing. So, what kinds of media are suitable for stainless steel knife gate valves? Let’s take a look at the details below.

Stainless steel knife gate valves are suitable for a wide variety of media, including gold ore powder, tailings, pulp, wood pulp, fibers, dust, chemically treated wastewater, sedimentation tanks, mineral sands, slag, coal slime, asphalt, material bin outlets, fruits, and other media such as grains, cement slurry, slaughterhouse wastewater, pneumatic conveying pipelines, or beer brewing processes. Generally speaking, knife gate valves are ideal for media with high viscosity and containing solid particles.

So, someone might ask: If knife gate valves can be used with so many different media, why don't all industries related to the aforementioned media adopt knife gate valves? The answer is actually that stainless steel knife gate valves are more expensive than conventional gate valves. As a result, some related industries have opted for the cheaper, conventional gate valves instead.

Stainless Steel Knife Gate Valve The working principle

Due to this design feature, knife gate valves become invaluable in applications involving viscous fluids, slurry, and other flowable substances that can cause impact. Today, many processing plants rely on knife gate valves, which come in large sizes and can easily handle light oils, heavy oils, varnishes, slurries, wastewater, and pulp. It’s important to note, however, that there are indeed low-pressure limitations, and the valve is designed so that once the blade cuts through the material it’s handling, the blade is sealed by an elastomeric gasket. Liquids can slide smoothly over these soft seals without interference; however, when solids or powders pass through the knife gate, bulky, dry materials will eventually accumulate in the soft seal located at the end of the gate plate. When this happens, the sealing ring can no longer close tightly. If this occurs, the seal must be replaced.

In the field of industrial production, everyone is concerned about... Stainless Steel Knife Gate Valve Its function should not be unfamiliar—for example, it can only be used for fully open and fully closed positions and cannot be used for regulation or throttling.

1. Actuation methods: manual, pneumatic, electric, hydraulic, electro-hydraulic, electro-pneumatic, and bevel gear, among others.

2. Materials: Stainless steel, carbon steel, cast steel, cast iron, and fluoropolymer-lined materials, among others.

3. Design: Available in two types—hidden stem and exposed stem.

4. Sealing: Various sealing materials available, including single-sided sealing, double-sided sealing, soft sealing, and hard sealing.

5. Operational Performance and Installation: The structure is simple yet compact, with a highly rational design. It features small size, light weight, reliable sealing, and easy disassembly. Various types of deposits on the sealing surfaces can also be easily removed. The operating temperature ranges from -29°C to 650°C, and the operating pressure is between 1.0 MPa and 2.5 MPa.

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?