Bevel gear transmission system: Labor-saving and space-fit for low-pressure scenarios
Transmission structure design It adopts a bevel gear (bevel gear) reduction mechanism. The driving gear (connected to the handwheel) and the driven gear (connected to the valve stem) mesh at 90°, with a transmission ratio of 1:3 to 1:8 (adapted to the diameter of DN100 to DN2000), which can amplify the manual operating force by 3 to 8 times. A single person can drive the opening and closing of large-diameter double gate plates (for example, the operating torque of the DN1200 model is ≤200N). The transmission box adopts a sealed structure made of cast iron, with built-in lithium-based grease, which is dust-proof and water-proof, and suitable for outdoor or humid working conditions. ​
Space optimization advantages: Bevel gear transmission can achieve "lateral handwheel operation" (different from the longitudinal operation of spur gears). When the valve is installed on the side or below the pipeline, there is no need to reserve the top operation space. Compared with spur gear transmission, it saves 50% of the longitudinal installation space and is suitable for narrow positions such as the bottom of pipe galleries and the bottom of equipment. ​
Operation and protection: The handwheel is made of detachable cast steel or engineering plastic, with an anti-slip texture on the surface. The top of the transmission box is equipped with a dust cover and the bottom has an oil drain hole. Regularly replacing the lubricating grease can extend its service life. For some large-diameter models (DN1000 and above), a "torque indicator" is installed beside the transmission box to display the operating torque in real time, preventing excessive force from damaging the seals. ​
3. Parallel double gate plate soft seal core: Low-pressure zero leakage design
Double gate structure: Parallel double gates are adopted, made of ductile iron QT450-10 (with surface plastic spraying for anti-corrosion) or stainless steel 304 (for corrosion resistance requirements). A compression spring (made of 65Mn) is set between the two gates. The spring force continuously pushes the gates to press the cover tightly to both sides, compensating for the wear of the sealing parts or the deformation of the valve body, ensuring long-term reliable sealing. "Nylon guide blocks" are set on both sides of the gate plate, with a fit clearance of no more than 0.15mm with the guide groove on the inner wall of the valve body, to prevent the gate plate from shifting and causing sealing misalignment. ​
Soft seal design: The sealing component is a "valve body sealing groove rubber sealing ring" structure. The material of the sealing ring is ethylene propylene diene monomer (EPDM) or nitrile rubber (NBR), which is fixed in the valve body sealing groove through embedded or vulcanization bonding. The cross-section of the sealing ring is "U-shaped" or "lip-shaped". When closed, the double gate plates squeeze the sealing ring to form a "bidirectional surface seal", with a leakage rate of ≤0.01×DN mm³/s (conforming to the GB/T 13927 V-level zero leakage standard), and it is suitable for scenarios with high sealing requirements such as tap water and drinking water. EPDM sealing rings can withstand temperatures ranging from -40 ℃ to 120℃ and are resistant to aging. NBR sealing rings are oil-resistant and weakly alkaline, making them suitable for industrial wastewater containing a small amount of oil stains.