Structural features

1. Electric drive core system: Efficient power and precise control
The drive unit is composed of an electric actuator (including a motor, a reducer, and a torque controller) and a valve stem transmission mechanism. The motors are mostly three-phase asynchronous motors (with power ranging from 0.37kW to 5.5kW, adapted to the diameter), paired with worm gears or gear reducers, and the output torque is 100N · m to 5000N · m, which can drive large-diameter gate plates to open and close smoothly. The actuator integrates travel control and torque protection. It precisely controls the fully open/fully closed position of the gate plate through the travel switch (error ≤1mm). When the torque exceeds 1.2 to 1.5 times the rated value, it automatically stops to prevent the gate plate from getting stuck or the valve stem from being damaged. ​
Control and adaptability It supports dual control modes of "local manual and remote automatic". Locally, emergency operation can be carried out through the actuator handwheel. Remotely, it can be connected to the PLC or DCS system to achieve opening degree adjustment (0%-100%), status feedback (such as fully open/fully closed signals), and fault alarm (motor overload, power failure). Suitable for unmanned industrial pipelines (such as those in the petroleum, chemical, and power plant industries); Some models of actuators are equipped with an IP67 protection rating and can operate stably in outdoor, damp or dusty environments. ​
2. Concealed rod transmission structure: Compact design and space adaptation
The connection between the valve stem and the gate plate: It adopts the "concealed stem internal thread transmission" design. The valve stem does not rise or fall with the gate plate (different from the exposed stem gate valve). The lower end of the valve stem is connected to the gate plate through T-shaped threads or wedge-shaped grooves, and the upper end meshes with the output shaft of the electric actuator reducer. When opening and closing, the electric actuator drives the valve stem to rotate, and through threaded transmission, it moves the gate up and down. The valve stem is always hidden inside the valve body. The overall structure is compact, occupying only 60% to 70% of the installation space of the rising stem gate valve. It is suitable for scenarios where the space above the pipeline is limited (such as pipe galleries and areas with dense equipment). ​
Sealing and protection: Multi-layer packing seals (usually flexible graphite PTFE combined packing) are set between the valve stem and the valve body. The packing box is tightened by cover bolts, and the sealing performance complies with the GB/T 13927 IV grade standard, preventing the medium from leaking along the valve stem. The surface of the valve stem is treated with chrome plating or nitriding (hardness HV≥800) to reduce friction loss with the packing, extend the service life of the packing and the valve stem, and be suitable for high-pressure (PN16-PN100) working conditions. ​
3. Wedge-type gate seal: The core structure suitable for high pressure
Gate plate design The structure adopts elastic wedge or rigid wedge type (elastic wedge type is mostly used for medium and small diameters, while rigid wedge type guide blocks are used for large diameters). The materials are cast iron HT250, carbon steel WC6 or stainless steel 304/316L. The sealing surface of the gate plate is surfacing with hard alloy (such as Stellite 6) or sprayed with ceramic coating, with a hardness of HRC≥55 Wear-resistant and erosion-resistant; The elastic wedge gate compensates for the processing error of the valve body's sealing surface through slight deformation, while the rigid wedge gate ensures precise adhesion of the sealing surface through double guide blocks, making it suitable for high-pressure media such as steam and oil products. ​
Sealing principle: When closed, under the thrust of the valve stem, the wedge surface of the gate plate closely adheres to the sealing surface of the valve body, forming a hard metal-to-metal seal (some low-pressure models are soft seals, with the gate plate covered with rubber). The sealing specific pressure increases with the rise of the medium pressure, and the leakage is ≤0.1×DN mm³/s, meeting the requirements of high-pressure cut-off conditions. When the gate is opened, it is fully lifted to the top of the valve body chamber, with the flow path straight and unobstructed. The flow resistance coefficient is ≤0.1, making it suitable for high-flow transportation scenarios. ​
4. Valve body and connection structure: High pressure and compatibility optimization
Valve body design: It adopts integral casting (carbon steel, stainless steel) or forging (high-pressure models) process. The wall thickness of the valve body is designed according to the PN pressure grade (for example, the wall thickness of the PN40 model is 30%-50% thicker than that of the PN16 model), and it passes the water pressure test (the test pressure is 1.5 times the nominal pressure) to ensure no leakage. The flow channel is direct current, with a smooth inner wall (roughness Ra≤1.6μm), reducing medium deposition and resistance, and is suitable for media such as oil, steam, and water. A drainage hole is provided at the bottom of the valve body, which can regularly discharge the accumulated impurities in the chamber to prevent the gate plate from getting stuck. ​
Flange connection In accordance with the standards of GB/T 9119, ANSI B16.5 or API 600, the sealing surface is a raised surface (RF), concave and convex surface (MFM) or tenon and groove surface (TG). The number of bolt holes matches the diameter of the hole (for example, for the DN300 PN40 model, there are 16 bolt holes with a diameter of φ27mm). Compatible with high-strength bolts (grade 8.8-12.9), it ensures that the flange connection has no leakage under high pressure and meets the standardized installation requirements of industrial pipelines. ​
5. Structural differences adapted to working conditions: Customized design as needed
High-pressure and high-temperature working conditions (such as power plant steam pipelines) : Rigid wedge gate plates (double guide) are adopted. The valve body and the gate plate are made of chromium-molybdenum steel WC9 material. The sealing surface is surfacing with hard alloy. The electric actuator is equipped with a high-temperature heat dissipation device, suitable for a temperature range of -29 ℃ to 425℃ and a pressure rating of PN40 to PN100. ​
Corrosion-resistant working conditions (such as chemical acid and alkali pipelines) The valve body and gate plate are made of stainless steel 316L, the valve stem is made of 316L stainless steel, the packing is acid and alkali resistant PTFE combined packing, and the electric actuator housing is made of 304 stainless steel to prevent medium corrosion. It is suitable for a temperature range of -40 ℃ to 180℃ and a pressure rating of PN10 to PN40. ​
Low-pressure large-diameter working conditions (such as municipal water supply) : Elastic wedge gate plates (soft seals) are adopted, the valve body is made of ductile iron QT450-10, and the electric actuator is simplified (small power motor), which is more cost-effective and suitable for pressure grades of PN10-PN16 and large-diameter requirements of DN500-DN2000. ​