Knife type gate valve, as the name implies, has a knife-shaped oblique cutting plate at the bottom of the valve body, which has the function of cutting off the mediums, so that the valve can close without being blocked by the mediums. This knife gate valve is generally used to open and close the flow of pulp, coal ash, chemical raw materials, sewage, food and other mediums. Its pressure range is generally used within 1.6Mpa, and its working temperature is generally used below 120℃. special material can be used for high temperature.
This knife type gate valve has significant advantages such as lighting switching, reliable sealing performance, good elastic performance, and long service life. It can be widely used in tap water, sewage, construction, petroleum, chemical industry, food, medicine, textile, electric power, shipbuilding, metallurgy, energy systems and other pipelines as regulating and shutting-off devices.
Types of knife type gate valves:
There are various types of knife gate valves, here, we are going to introduce you some widely used types: like lug type knife gate valves, wafer type knife gate valves, unidirectional sealing knife gate valves, bidirectional sealing knife gate valves, soft sealing knife gate valves, metal to metal hard sealing knife gate valves, extended stem knife gate valves, plate type gate valves, knife type mud gate valves, knife type slag discharge gate valve, single clamp slurry gate valve, and manual single clamp knife type gate valves,rising stem knife gate valves and non rising stem knife gate valve, etc.
Main technical parameters of knife gate valves:
1. nominal pressure: 1.0Mpa, 1.6Mpa
2. Nominal diameter: DN50-DN800
3. Shell testing pressure: 1.5Mpa, 2.4Mpa
4. Sealing testing pressure: 1.1Mpa, 1.8Mpa
5. Working temperature: ≤900℃.
6. Applicable mediums: pulp, sewage, coal slurry, ash, slag-water mixture.
7. Main components of knife gate valve: valve body, bonnet, valve plate, stem, sealing surface,etc;
8. Body material options: F55, F53, 2205, CF3M, CF8M, CF8, WCB, GGG40(cast iron, ductile iron, carbon steel, stainless steel)
9. Wedge disc material: F55, F53, 2205, SS310, SS316L, SS316, SS304;
10. Sealing material: NBR, EPDM, FKM, PTFE, Graphite, metal;
11. Operating options: Manual, electric, pneumatic, hydraulic, sprocket, electrohydraulic, gear, lever handle.
Characteristics of knife gate valve:
1. the face to face length of knife gate valve is short, which can save manufacturing materials and can greatly reduce the overall weight of the whole pipeline system.
2. The knife gate valve occupies a small effective space, can effectively support the strength of the pipeline, and can reduce the possibility of pipeline vibration;
3. The wedge plate is made of austenitic stainless steel, which greatly improves the corrosion resistance and can effectively prevent the leakage of the sealing surface caused by the corrosion of the wedge plate;
4. The upper sealing packing of knife gate valve is using flexible PTFE, which is reliable in sealing and flexible in operation;
5. The plate of knife gate valve has the function like a knife, which can effectively cut off all kinds of sundries in the medium;
6. If the sealing material is using metal hard material, like stainless steel material, and the valve plate is spray-welded, the knife gate valve can be more suitable for high temperature and high pressure working conditions;
Advantages of knife type gate valves:
1. the fluid resistance of knife gate valve is small, and the sealing surface is less eroded and rarely eroded by the medium.
2. The knife gate valve can be opened and closed labor-saving;
3. The flow direction of the medium in knife gate valve is not restricted, the flow is not disturbed and the pressure is not reduced;
4. The knife gate valve is durable and easy and convenient to operate;
5. The shape of knife gate valve is simple, and its face to face length is short, and it has wide applications;
Disadvantages of knife type gate valves:
1. for knife gate valves, it is easy to cause erosion and scratches between the sealing surfaces, and it is difficult to maintain;
2. The knife gate valve has large overall outline size, a certain space is required to open, and its opening and closing time is long;
3. The structure of knife gate valve is more complicated;
Applications of knife type gate valves:
Knife gate valve has a good shearing effect due to the use of a knife-shaped plate, which is most suitable for difficult-to-control fluids such as pulp, power, and fiber. Knife type gate valve is widely used in paper making, petrochemical, mining, drainage, food and other industries. Knife type gate valve has various types of valve seats to select, and can also be equipped with handle lever, hand-wheel, electric actuator, pneumatic actuator according to the needs of on-site control to realize the automatic operation of the knife gate valve.
for more informations or prices about wafer types knife gate valves, lug type knife gate valves, flanged knife gate valves, stainless steel knife gate valves, cast iron knife gate valves, carbon steel knife gate valves, soft sealing knife gate valves, metal to metal hard sealing knife gate valves, unidirectional sealing knife gate valves, bidirectional sealing knife gate valves, if you have no idea what kind of knife gate valves should be used in your pipelines, kindly contact us, professional advices will be offered: