Actuation methods, sealing methods, and application ranges of knife gate valves

Release time:

2022-06-07

Knife gate valve (also known as knife-type gate valve, knife-gate valve, slurry valve, or mud valve)


The knife gate valve—also known as a knife-type gate valve, knife-disc gate valve, slurry valve, or mud valve—actually features a valve body without a cavity. The gate plate moves up and down within lateral guide slots and is tightly pressed against the valve seat by lug projections at the bottom. When stringent sealing requirements for the medium are necessary, an O-ring-sealed valve seat can be used to achieve bidirectional sealing. Knife gate valves have a compact installation footprint, operate at low working pressures, are less prone to debris accumulation, and offer excellent cost-performance.

When a knife gate valve is closed, the sealing surfaces are pressed against the valve seat on the opposite side by the pressure of the medium itself, thereby ensuring a tight seal. This is what we commonly refer to as self-sealing. In most cases, however, gate valves rely on forced sealing—meaning that when the valve is closed, an external force must be applied to forcibly press the gate against the valve seat in order to guarantee the integrity of the sealing surfaces. In piping systems, this type of valve should generally be installed vertically.

1. Actuation methods for knife gate valves include manual, chainwheel, electric, pneumatic, hydraulic, bevel gear, electro-hydraulic, and electro-pneumatic-hydraulic types.

II. Valve Body Type: There are two types—rising stem and non-rising stem.

3. Material of knife gate valves: Available in cast iron, cast steel, carbon steel, stainless steel, and fluoropolymer-lined materials.

4. Seal types for knife gate valves: available in various materials, including hard seals, soft seals, single-sided seals, and double-sided seals.

The ultra-thin knife gate valve features a compact size, low flow resistance, light weight, ease of installation, and simple disassembly. It addresses the issues commonly encountered with conventional gate valves, flat-plate gate valves, ball valves, globe valves, control valves, butterfly valves, and other similar types of valves—such as high flow resistance, heavy weight, difficult installation, and large footprint. The introduction of the knife gate valve has effectively replaced traditional shut-off and control valves.

V. The application range of knife gate valves is:

1. Mining, coal washing, and the iron and steel industry—can be used for coal-washing pipelines, slurry-filtering pipelines, ash-discharge pipelines, and more.

2. Purification device—can be used for wastewater, slurry, sewage, and clear water containing suspended solids;

3. Paper industry—can be used for pulp and slurry mixtures of various concentrations;

4. Power plant ash removal—can be used for ash and slag slurry.

                     539d455b-d498-4f69-97ed-c5bd6acfe009.jpg

Related News

The slurry valve manufacturer introduces to you the stainless steel knife gate valve and the pneumatic knife-type gate valve.

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?

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.

2023-02-02

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

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.

2023-01-04

Online Message

If you have any questions, please contact us!

Submit