The Welding Neck Flange (WNF) is widely recognized as the most reliable flange design in the piping industry, distinguished by its long, tapered hub. At Jiangyin Zhonghai Precision Machinery Co., Ltd., our WNFs are specifically engineered for extreme environments characterized by high pressure, fluctuating temperatures, or severe mechanical stress.

By butt-welding the flange hub to the pipe, stress is effectively transferred to the pipeline itself, significantly reducing stress concentration at the base of the flange. Leveraging our "Forging-to-Finishing" integrated production capability, we provide premium flanges with pressure ratings up to 2500lb and diameters up to 4 meters, ensuring your system remains secure under the most demanding loads.

Core Advantages
·Integrated Vertical Manufacturing: We operate a complete production line including in-house forging, heat treatment, CNC machining, and physical/chemical testing. This ensures superior grain structure and mechanical properties compared to simple machined parts.
·Global Certifications: ISO 9001 certified with PED (Pressure Equipment Directive) and TS (Special Equipment Licensing) credentials, meeting the strict regulatory requirements of international markets.
·Advanced Customization: We specialize in "Build-to-Print" services. Whether you require exotic materials or unique dimensions (OD, ID, thickness, bolt circle), we provide rapid evaluation and high-precision delivery.
·Massive Scale Capacity: Supporting sizes from 1/2" to 60" with a single-component weight capacity of up to 10 tons, making us the ideal partner for heavy infrastructure and heavy industrial sectors.

Key Features
·Optimal Stress Distribution: The tapered neck provides a smooth transition of stress, significantly enhancing the fatigue resistance of the flange in systems subject to repeated bending or vibration.
·Forged Integrity: Our forging process ensures continuous metal grain flow along the contours of the flange, maximizing tensile strength and impact resistance.
·Precision Sealing Faces: Utilizing advanced CNC turning, we maintain strict control over the roughness of sealing faces (RF, RTJ, etc.), ensuring a perfect gasket seal and zero-leakage performance.
·Rigorous Non-Destructive Testing (NDT): For critical services, we offer Ultrasonic (UT), Magnetic Particle (MT), and Radiographic (RT) testing to guarantee a defect-free internal structure.

Applications
Zhonghai Welding Neck Flanges are the trusted choice for safety-critical industries:
·Oil & Gas: High-pressure transmission lines, manifold stations, and wellhead equipment.
·Chemical & Refining: High-temperature reactors and vessels handling flammable or corrosive media.
·Power Generation: Steam piping and boiler systems in thermal and nuclear power plants.
·Pressure Vessels: Serving as robust equipment nozzles capable of handling complex mechanical and thermal stresses.