Knife gate valve characteristics and purchase advice

Knife gate valve, also known as knife valve, knife gate valve, slurry valve, mud valve, its opening and closing pieces is the gate, the direction of movement of the gate and the fluid perpendicular to the cutting edge by cutting the fiber material knife gate Medium, the gate has two sealing surface, the most commonly used gate valve form the two sealing surface wedge, wedge angle varies with the valve parameters, usually 5 °, wedge gate valve gate can be made into a The whole, called the rigid gate; can also be made to produce a small amount of deformation of the gate, to improve its technology to make up for sealing surface angle in the process of deviation, this gate is called elastic gate. The valve body does not actually exist in the chamber. The gate raises and lowers in the side guide groove and is pressed against the valve seat by the lugs on the bottom. To achieve high medium tightness, an O-ring seat is available Two-way seal. Knife gate valve has a smaller installation space, low work pressure, easy accumulation of debris, the price is lower.

When the knife-type gate valve is closed, the sealing surface can only rely on the medium pressure to seal, that is, self-sealing by relying on the medium pressure to press the sealing surface of the gate to the valve seat on the other side to ensure the sealing surface. Most of the gate valve is forced seal, that is, when the valve is closed, it must rely on external force to force the gate to the valve seat to ensure the sealing surface of the seal. This type of valve should be installed vertically in the pipeline.

Knife gate valve drive mode: manual, sprocket, electric, pneumatic, hydraulic, bevel gear, electro-hydraulic and pneumatic drive and other driving methods. Knife gate valve shape: bright rod, dark rod two. Knife gate valve material: cast iron, cast steel, carbon steel, stainless steel, such as fluorine lining. Knife gate valve seal: hard seal, soft seal, single seal, double seal and other material seal.

Slim knife gate valve with its small size, small flow resistance, light weight, easy installation, easy removal and other advantages of the complete settlement of the ordinary gate valve, ball valve, globe valve, globe valve, butterfly valve and other types of valve flow resistance , Heavy weight, difficult installation, large area and other difficult problems. After the knife gate valve appears, a large number of general-purpose cut-off valves and regulating valves have been replaced. Today, the world's largest amount of knife gate valve is the United States and Japan.

Knife-type gate valve has the advantages of simple and compact structure, reasonable design, light materials, reliable sealing, light and flexible operation, small size, smooth passage, small flow resistance, light weight, easy installation, easy disassembly and other advantages. Gate valves, globe valves, regulating valves, butterfly valves, ball valves and other valves of heavy weight, large flow resistance, large area, hard to install and other difficult problems, can replace the general cut-off valve and control valve, the working pressure 1.0MPa- 2.5MPa, Temperature -29-550 ℃ under normal circumstances. Knife gate knife gate has a shear function, scraping the sealing surface of the adhesive, automatically remove debris, stainless steel gate to prevent corrosion caused by the seal leak.

Knife-type gate valve for mining coal-fired power plant, slagging, urban sewage treatment, food, paper, medicine, petroleum, chemical and other oil, water, steam pipeline, connect or cut off the pipeline slurry, gold Powder, Ores, Slag, Slime, Pulp, Wood Pulp, Tailings, Fibers, Dust, Chemical Wastewater, Sedimentation Tanks, Bitumen, Silo Exports, Fruits, Cereal, Slaughterhouse Wastewater and other media.

Knife gate valve structure

Thirteen characteristics of knife gate valve:

1, can improve the sealing surface of the shutter can be scraped off the sealing surface of the adhesive, automatically remove debris.

2, stainless steel gate to prevent corrosion caused by leakage seal, grinding and polishing can get better sealing effect. The bottom end of the blade is processed into a knife-edge shape, which has the function of cutting off the soft materials such as fiber, pulp and wood pulp and has a good function of opening and closing. In the upper edge of the blade is installed a hard Teflon scraper to prevent dust, gravel and other abrasives into the stuffing box, can significantly increase the life of the knife.

3, stainless steel body durable, body rib design to improve the body strength, snail use hoist more quickly.

4, the overall stainless steel, to prevent corrosion damage. The valve body and packing culvert are all precision castings, of which the valve body is flanged and integrally cast, the material can be selected according to user needs 304,316,316L, WCB, 2Crl3, PTFE ring reinforced PTFE material, corrosion resistance, Wear-resistant, non-stick residue. Thirteen Characteristics of Knife Gate Valve

5, full circular DC channel design does not slag, no jamming.

6, science on the packing seal design, so that the seal is safe and effective, durable.

7, short structure length, can save raw materials, installation space, but also effectively support the pipe strength.

8, triangular bracket to save raw materials, to ensure the mechanical properties needed.

9, knife-type gate valve body guide block to make the correct movement gate. Squeeze block to ensure effective sealing of the gate.

10, knife-type gate valve can also choose the drive mechanism.

11, V-type gate can be used as a control valve.

12, compact design, occupy a small space, light weight, cheap, easy to install, wear anti-blocking measures to improve, easy maintenance, easy to use and long life, and optional drive.

13, the valve plate has five support points, so that the valve plate has a good self-aligning. When the valve is closed, and withstand back pressure, the valve plate does not shift.

Knife gate valve installation and use instructions

1, knife gate valve before installation to check the valve cavity and sealing surface and other parts, do not allow dirt or grit attached;

2, the bolts of the connection parts, require uniform tightening;

3, check the packing parts require compression, both to ensure that the packing seal, but also to ensure that the gate open flexible;

4, the user before installing the valve, the valve must be proofing the model, connecting size and pay attention to the flow of media to ensure consistency with the requirements of the valve;

5, the user installs the valve, must reserve the necessary space that the valve drives;

6, the wiring of drive device shall be carried out according to the circuit diagram;

7, knife valve must be regularly maintained, not free to crash and squeeze, so as not to affect the seal.

Knife gate valve precautions

Knife-type gate valve opening and closing pieces is the gate, gate direction of motion and fluid perpendicular to the knife gate valve can only be fully open and fully closed, can not be adjusted and throttling. Gate has two sealing surfaces, usually 50, wedge gate valve gate can be made as a whole, called the rigid gate; can also be made to produce a small amount of deformation of the gate to improve its technology to make up Sealing surface angle in the process of deviation, this gate is called a flexible gate. Knife gate valve closed, the sealing surface can only rely on media pressure to seal. Most knife-type gate valve is a mandatory seal, that is, when the valve is closed, it must rely on external force to force the gate to the valve seat to ensure the sealing surface of the seal.

Knife gate valve purchase advice

1. Users purchase, must indicate the nominal valve through, the pressure and the required standard valve connection;

2. The valve required for special needs, must indicate the special size, special materials and other parameters.