Knife type gate valve-operating methods,application and maintenance

Knife type gate valve is one special widely used gate valve, which has the knife-shaped valve plate to cut off the medium flow and can remove the medium debris automatically. 

Today we are going to introduce the operating methods, applications and maintenance of knife type gate valve. 

Operating methods of knife type gate valve

According to different operating methods used, there are manual knife type gate valves, chain hand wheel knife gate valve, electric actuated knife gate valve, pneumatic actuated knife gate valve, hydraulic knife gate valve, bevel gear knife gate valve, electric control hydraulic knife gate valve, air-hydraulic knife gate valve,etc. 

According to the stem structure of knife gate valves, there are rising stem knife gate valve and non rising stem knife gate valve. 

With different body material used, there are cast iron knife gate valves, cast steel knife gate valve, carbon steel knife gate valve, stainless steel knife gate valve. 

With different sealing structures, there are metal hard sealing knife gate valves, soft sealing knife gate valve, unidirectional sealing knife gate valve, bidirectional sealing gate valve,etc. 

Advantages and applications of knife type gate valve:

The knife type gate valve has the advantages of small size, small flow resistance, light weight, easy installation and easy disassembly,etc. Which completely solves the problems of ordinary gate valve, ball valves, globe valves, regulating valves, butterfly valves and other types valves with large flow resistance, heavy weight, difficult to install, large area and other problems. After the appearance of the knife gate valve, a large number of general purpose shut off valves and regulating valves have been replaced. 

1. knife gate valve can be used for coal washing pipelines, slurry filtering pipelines, ash discharge pipelines in mining, coal mining and steel industries. 

2. Knife gate valves can be used for waste water, mud, dirt and clarified water with suspended solids as a purification device. 

3. Knife type gate valve can be used in paper industry-for any consistency pulp, material water mixture. 

4. Knife gate valve can be used for ash removing in power station and for ash slurry. 

Installation instruction of knife gate valve: 

1. before the installation of knife gate valve, it is necessary to check the inner cavity and sealing surface of the knife gate valve, to ensure there are no dirt or sands. 

2. All connect bolts should be tightened evenly. 

3. Before the installing of knife gate valve, check the model no, connect size and medium flow direction of the knife gate valve, to ensure those specifications are consistent with the valve requirements. 

4. Check the packing part to ensure the sealing performance of the knife gate valve, and also ensure the valve plate can be opened and closed flexibly. 

5. When installing the knife gate valve, the necessary operating space must be left out. 

6. The wiring of the driving device must be connected according to the wiring diagram. 

7. After the installing of the knife gate valve, the knife gate valve should be maintained regularly, and should not be bumped and squeezed, to avoid the damage of the sealing surface. 

Maintenance of knife gate valve: 

1. the hand wheel, handle and other transmission structures are not allowed to be used for lifting, and collision is strictly prohibited. 

2. The double plate knife gate valve should be installed vertically, which means, the valve stem should be in the vertical position and the hand wheel is at the top. 

3. For the knife gate valves with transmission structure, the valve should be installed according to the provisions of product instruction manual. 

4. If that knife gate valve is opened and closed frequently, lubricate it at least once a month. 

for technical parameters about knife wedge gate valves, like soft sealing knife gate valves, metal hard sealing knife gate valves, unidirectional sealing knife gate valves, bidirectional sealing knife gate valves, cast iron knife gate valves, carbon steel knife gate valves, stainless steel knife gate valves, kindly contact us: