Structural features

1. Hydraulic drive core system: Precise power transmission and control
Hydraulic power unit: It is composed of a hydraulic pump station (including motor, oil pump, oil tank, relief valve, and directional control valve), hydraulic pipelines, and hydraulic cylinders (or hydraulic motors). The pumping station provides stable hydraulic oil (with a working pressure of 10-16 mpa). The flow direction of the oil is controlled by a directional control valve, which drives the hydraulic cylinder to extend or contract or the hydraulic motor to rotate, thereby opening and closing the valve stem and butterfly plate. The relief valve can limit the maximum pressure of the system, prevent overloading from damaging components, and meet the driving force requirements of valves of different diameters (DN100-DN2000). ​
Synchronous and regulating structure: For large-diameter valves (DN800 and above), a symmetrical arrangement of double hydraulic cylinders is mostly adopted. Synchronous valves are used to ensure that the extension and retraction speeds of the hydraulic cylinders on both sides are consistent, avoiding the deformation of the butterfly plate due to eccentric loading. The hydraulic system is equipped with a throttle valve, which can adjust the opening and closing speed of the butterfly plate (usually the full opening/full closing time is 5 to 30 seconds), preventing water hammer impact caused by rapid opening and closing, and is suitable for working conditions such as water supply, drainage, and pumping stations that are sensitive to flow rate. ​
2. Core structure of check function: Key design for preventing backflow
Check seal assembly: It adopts a combination of "butterfly plate seal pair check mechanism", with the sealing pair being either a soft seal (EPDM/NBR rubber) or a hard seal (hard alloy/ceramic), precisely adhering to the edge of the butterfly plate. Check mechanisms are mostly of the counterweight type, spring type or hydraulic locking type: The counterweight type connects the counterweight through a butterfly plate. When the medium flows in the forward direction, it pushes the butterfly plate to overcome the torque of the counterweight to open; when it flows in the reverse direction, the gravity of the counterweight drives the butterfly plate to close quickly. The spring type relies on the pre-tightening force of the spring, and the reverse medium pressure superimposes the spring force to accelerate the sealing. The closing response time is ≤0.5 seconds, and the leakage complies with the GB/T 13927 Class IV standard. ​
One-way limit structure: The valve body is equipped with limit blocks or retaining rings to restrict the maximum opening Angle of the butterfly plate (usually 60°-90°), and at the same time prevent the butterfly plate from overturning excessively during reverse flow and damaging the sealing surface. Some models are equipped with one-way bearings at the connection between the butterfly plate and the valve stem, which only allow the butterfly plate to open when rotating in the forward direction and automatically lock when rotating in the reverse direction, providing double protection for the check function. ​
3. Valve body and butterfly plate structure: Optimized design adapted to dual functions
Valve body design: Cast from ductile iron QT450-10, carbon steel WCB or stainless steel 304. The flow channel is a straight-through streamlined type, with a smooth inner wall (roughness Ra≤1.6μm), reducing medium resistance and energy consumption. Flange connections comply with GB/T 9119 or ANSI B16.5 standards. The sealing surface is raised face (RF) or concave and convex face (MFM), and is compatible with PN10/PN16/PN25 pressure grades, meeting the requirements of industrial, municipal and water conservancy projects. ​
Butterfly plate structure: Vertical plate or inclined plate (for some models) is adopted, with materials of ductile iron (surface plastic-sprayed) or stainless steel. The thickness is optimized through mechanical calculation to ensure no deformation under forward pressure. The edge of the butterfly plate is treated with an arc transition to prevent the sealing surface from being scratched during opening and closing. The valve stem and the butterfly plate are connected by a key conical surface fit, with a fit clearance of no more than 0.05mm, ensuring that the butterfly plate rotates synchronously during hydraulic control drive and has a precise response during check. ​
4. Control and protection auxiliary structure: Enhanced safety and convenience
Control logic component: Equipped with a hydraulic lock (hydraulic control check valve), once the butterfly plate is in place, it locks the position of the hydraulic cylinder/motor to prevent the butterfly plate from shifting due to pressure loss in the hydraulic system. The system integrates pressure sensors and limit switches to monitor hydraulic pressure and butterfly plate opening in real time. It can be linked with the PLC control system to achieve remote monitoring, automatic opening and closing, and fault alarm (such as insufficient hydraulic oil and seal leakage), and is suitable for unmanned pumping stations. ​
Emergency and maintenance design: Manual emergency operation devices (such as manual pumps, handwheels) are installed. When the hydraulic system malfunctions, the butterfly plate can be manually driven to open and close, ensuring the normal operation of the pipeline system. A drainage hole is reserved at the bottom of the valve body, which can regularly discharge the accumulated impurities inside. The hydraulic cylinder/motor is equipped with an exhaust valve to prevent air from entering the hydraulic system and causing transmission jamming, thereby extending the service life of the equipment. ​
5. Structural differences adapted to working conditions: Customized optimization as needed
Low-pressure and high-flow working conditions (such as municipal drainage) : A soft-sealed heavy hammer check structure is adopted. The valve body material is ductile iron. The hydraulic system is simplified (driven by a single hydraulic cylinder), which is lower in cost. Moreover, the rubber seal is suitable for sewage medium, and the check effect is stable. ​
High-pressure corrosion-resistant working conditions (such as chemical and petroleum industries) : It adopts a hard-sealed (stainless steel surfacing with hard alloy) spring-type check structure. The valve body and butterfly plate are made of stainless steel 316L material. The hydraulic system is equipped with corrosion-resistant hydraulic oil and stainless steel pipelines. The check mechanism responds faster and can resist the impact and corrosion of high-pressure media. It is suitable for a temperature range of -40 ℃ to 300℃. ​