Forged steel gate valve can withstand high pressure and high temperature. It can be used in power plants.  The stainless steel of the stainless steel gate valve is acid and alkali resistant cast steel, which is different from stainless steel. Cast steel cannot be acid and alkali resistant. It can only be used on ordinary pipelines.  The opening and closing part of the stainless steel gate valve is a gate. The movement direction of the gate is perpendicular to the direction of the fluid. The gate valve can only be fully opened and fully closed, and cannot be adjusted or throttled.  The gate has two sealing surfaces. *The two sealing surfaces of the commonly used model gate valve form a wedge. The wedge angle varies with valve parameters, usually 50, and 2°52' when the medium temperature is not high.  The gate of the wedge gate valve can be made into a whole, called a rigid gate; it can also be made into a gate that can produce slight deformation to improve its manufacturability and make up for the deviation of the sealing surface angle during the processing.  The plate is called an elastic gate.  Stainless steel materials are divided into 304 stainless steel, 316 stainless steel, and 321 stainless steel.  The expression method is: Z41H-16P.

    The working principle of stainless steel gate valve 　　 gate valve moves linearly along with the valve stem, which is called lifting stem gate valve (also called rising stem gate valve).  Usually there is a trapezoidal thread on the lifting rod, through the nut on the top of the valve and the guide groove on the valve body, the rotary motion is changed into linear motion, that is, the operating torque is changed into operating thrust.  The sealing surface can be sealed only by medium pressure, that is, 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 of the sealing surface, which is self-sealing.  Most gate valves use forced sealing, that is, when the valve is closed, the gate must be forced against the seat by external force to ensure the sealing performance of the sealing surface.

    The characteristics of stainless steel gate valve 　　 1. Exquisite selection of materials, in line with relevant domestic and foreign standards, and high overall quality of materials.

    　　2. It meets the requirements of advanced standards at home and abroad, with reliable sealing, excellent performance and beautiful appearance.

    3. The sealing pair is advanced and reasonable. The sealing surface of the gate and the valve seat is made of Stellite cobalt-based cemented carbide with different hardness. The sealing is reliable, high hardness, wear resistance, high temperature resistance, and corrosion resistance.  , Good scratch resistance and long life.

    　　4. The valve stem has been quenched and tempered and surface nitriding treatment, which has good corrosion resistance, scratch resistance and wear resistance.

    　　5. It adopts a wedge-type elastic gate structure, a thrust bearing with medium and large diameters, which has low friction and is equipped with impact manual operation, which makes it easy to open and close.

    Execution standard of stainless steel gate valve: 　　 design and manufacture: GB12234 　　 structure length: GB12221 　　 flange size: GB9113 JB79 　　 pressure and temperature: GB9131 　　 test and inspection: GB/T13927 HB/T9092 stainless steel gate valve installation and maintenance: 1.  The transmission mechanism is not allowed to be used for lifting, and collision is strictly prohibited.

    　　2. The double gate valve should be installed vertically (that is, the valve stem is in the vertical position and the handwheel is on the top).

    　　3. Before opening the gate valve with a bypass valve, open the bypass valve (to balance the pressure difference between the inlet and outlet and reduce the opening force).

    　　4. The gate valve with drive mechanism should be installed according to the product manual.

    　　 5. If the valve is frequently opened and closed, lubricate at least once a month.

    　　 The opening and closing parts of the forged steel gate valve are the gate, the movement direction of the gate is perpendicular to the fluid direction, the gate valve can only be fully opened and fully closed, and cannot be adjusted or throttled.  The gate valve has two sealing surfaces. *The two sealing surfaces of the commonly used model gate valve form a wedge, and the wedge angle varies with valve parameters.  The gate valve drive modes are: manual, pneumatic, electric, gas-liquid linkage.  Gate valves are classified by material: cast iron gate valves, ductile iron gate valves, stainless steel gate valves, forged steel gate valves, etc.

    According to the sealing surface configuration, the gate structure can be divided into wedge gate valve and parallel gate valve. Wedge gate valve can be divided into: single gate, double gate and elastic gate; parallel gate valve can be divided into  Single gate type and double gate type.

    　　1) Parallel gate valve: The sealing surface is parallel to the vertical centerline, that is, a gate valve with two sealing surfaces parallel to each other.  In parallel gate valves, the structure with thrust wedge* is often common. There are double-sided thrust wedge between the two gates. This kind of gate valve is suitable for low pressure medium and small diameter (DN40-300mm) gate valves.  There are also those with a spring between the two gates. The spring can generate pre-tightening force, which is beneficial to the sealing of the gate.

    　　2) Wedge gate valve: a gate valve with a certain angle between the sealing surface and the vertical centerline, that is, the two sealing surfaces are wedge-shaped.  The inclination angle of the sealing surface is generally 2°52´, 3°30´, 5°, 8°, 10°, etc. The size of the angle mainly depends on the temperature of the medium.  Generally, the higher the working temperature, the larger the angle should be taken to reduce the possibility of wedging when the temperature changes.  In the wedge gate valve, there are single gate, double gate and elastic gate.  The single gate wedge gate valve has a simple structure and reliable use, but it has high requirements for the accuracy of the angle of the sealing surface, processing and maintenance are difficult, and the possibility of wedging when the temperature changes is high.  Double ram wedge gate valves are used more in water and steam media pipelines.  Its advantages are: lower accuracy requirements for the angle of the sealing surface, temperature changes are not easy to cause the phenomenon of wedging, and gaskets can be added to compensate when the sealing surface is worn.  However, there are many structural parts of this kind, which are easy to bond in the viscous medium and affect the sealing.  More importantly, the upper and lower baffles are prone to rust after long-term use, and the gates are easy to fall off.  The elastic gate wedge gate valve has the advantages of simple structure and reliable use. It can also produce a small amount of elastic deformation to compensate for the deviation of the sealing surface angle processing and improve the manufacturability. It has been widely used  use.