Structural features

1. Valve body structure: Enhanced pressure-bearing and anti-deformation design
The valve body is made by thick-walled integral casting (ductile iron QT450-10, carbon steel WCB) or welding (stainless steel 304/316L). The wall thickness is increased by 20%-30% according to the pressure grade (such as PN10/PN16/PN25) (compared with DN1200), and the structure is optimized through stress analysis. Avoid valve body deformation caused by medium pressure under large diameters; ​
The flow channel adopts an equal straight-through streamlined design, with an inner diameter strictly matching the nominal size of DN1600. The inner wall of the flow channel is polished (roughness Ra≤1.6μm) to reduce the flow resistance of the medium (such as municipal raw water, industrial wastewater, and natural gas), making it suitable for ultra-large flow transportation scenarios (such as main urban water supply pipes and main pipelines in chemical industrial parks). ​
2. Butterfly plate and Seal: Suitable for large-diameter sealing reinforcement
Butterfly plate: It adopts a three-eccentric structure (a must-have for large diameters, more reliable than double eccentric seals), and the material is high-strength alloy (such as stainless steel 316L with hard alloy coating). The thickness is 15%-20% higher than that of the DN1200 model. The force-bearing structure is optimized through finite element analysis to ensure that the butterfly plate does not warp during opening and closing. The edge is precisely turned, with a fit error of no more than 0.1mm to the sealing surface. When closed, it can meet the API 598V grade zero leakage standard. ​
Sealing surface: The soft seal adopts embedded ethylene propylene diene monomer (EPDM) or fluorine rubber (FKM), and the rubber cross-section is designed in a "U shape" to enhance the extrusion sealing performance. Hard seals are made by surfacing stainless steel with hard alloy (Stellite 6) or ceramic coating (Al₂O₃), and the width of the sealing surface is increased to 15-20mm (about 12mm for DN1200), which enhances wear resistance and service life. They are suitable for a wide temperature range of -40 ℃ to 500℃ and corrosive media. ​
3. Valve Stem and Drive: Stable transmission under Heavy loads
Valve stem It adopts a thickened solid double support structure (the top is connected to the drive end and the bottom is fixed by double bearings), with materials of 2Cr13 stainless steel (for normal working conditions) or 316L stainless steel (for corrosion-resistant working conditions), and the diameter is 25% larger than that of the DN1200 model (for example, DN1200 uses φ40mm). For DN1600, φ50mm is used, and the surface is treated with nitriding (hardness HV≥800) to prevent the bending or wear of the valve stem caused by the self-weight of the large-diameter butterfly plate. ​
Drive adaptation: Mainly driven by electric (multi-turn motor) or pneumatic (double-acting cylinder), equipped with a reducer and torque limiter to achieve slow opening and closing (opening and closing time ≥30 seconds to prevent water hammer impact). Electric drive can be equipped with an intelligent control system, supporting remote monitoring, torque protection and fault alarm. Manual drive is only used as an emergency backup (it needs to be equipped with a high-speed-ratio worm gear and worm to reduce operating force). ​
4. Flange connection: Standardized and installation compatible
The flange adopts the national standard GB/T 9119-2020 or the American standard ANSI B16.5. The sealing surface of the flange is concave and convex surface (MFM) or tenon and groove surface (TG) (which has stronger sealing performance compared to the raised surface RF). The number of bolt holes is increased to 24-32 (about 20 for DN1200). The hole diameter is increased (for example, from φ24mm to φ27mm), and high-strength bolts (such as 8.8 grade or 10.9 grade carbon steel bolts) are adapted to ensure that the flange connection has no leakage under large diameters and high pressure. ​
The flange end face is processed for parallelism (error ≤0.05mm/m) to facilitate precise connection with the pipe flange. During installation, metal wound gaskets (with inner rings) or graphite composite gaskets can be used to further enhance the sealing reliability. ​
5. Auxiliary structure: Specialized optimization for large diameters
Reinforcing ribs are added to both sides of the valve body (6 to 8 evenly distributed along the circumference of the flange) to enhance the strength of the connection between the valve body and the flange and prevent the flange from deforming when the installation bolts are tightened. ​
The bottom of the valve stem is equipped with a drain valve (DN20-DN32), which can regularly discharge the residual medium in the valve stem sealing cavity to prevent the corrosion of the valve stem caused by medium accumulation. Some models are equipped with a pressure detection interface (G1/2 thread) on the top of the valve body, which facilitates real-time monitoring of the pressure inside the valve and meets the maintenance requirements of large-diameter valves after long-term operation. ​