The Class 300 Welding Neck Flange (WN) is a critical engineered component designed for the most demanding industrial environments. Characterized by a long tapered hub that is butt-welded to the pipe, the WN flanges manufactured by Jiangyin Zhonghai Precision Machinery Co., Ltd. are designed to transfer stress from the flange to the pipe, significantly reducing stress concentration at the base of the hub.

Leveraging our robust in-house forging and precision machining capabilities, our Class 300 WN flanges exhibit exceptional performance under temperature fluctuations, high-pressure shocks, and shear forces. Whether adhering to standard ANSI B16.5 specifications or non-standard custom designs, we ensure every product operates with a high safety margin.

Core Advantages
·Optimal Stress Distribution: The tapered hub provides a smooth transition of pressure, enhancing the structural integrity of the piping system—ideal for high-pressure and fluctuating load environments.
·Vertically Integrated Manufacturing: Zhonghai manages the entire process from forging and heat treatment to CNC turning and testing. This ensures that the metal grain flow aligns with the flange profile, maximizing mechanical strength.
·Global Quality Certifications: ISO 9001 certified with PED (TÜV) and TS credentials, ensuring full compliance with international standards such as ASTM/ASME, EN, and API.
·Heavy-Duty & Custom Capabilities: Our range covers 1/2" to 60", with the capability to process precision forgings up to 4 meters in diameter and 10 tons in weight.

Key Features
·Butt-Weld Integrity: The butt-weld connection ensures strength equal to the pipe itself, and the weld joint is easily inspected via Radiographic Testing (RT).
·Extreme Condition Resilience: The Class 300 rating accommodates a wide range of pressure-temperature ratings, maintaining long-term sealing in high-pressure and cyclic service.
·Precision-Machined Faces: Available in RF (Raised Face), RTJ (Ring Type Joint), and more. CNC finishing ensures sealing surface roughness meets the most stringent industry standards.
·Full Material Traceability: Every product is issued with a complete Material Test Certificate (MTC), ensuring 100% traceability from raw ingot to finished part.

Applications
·Oil & Gas: Transmission pipelines, compressor stations, and separation units.
·Chemical & Refining: High-temperature reactors, heat exchangers, and corrosive media networks.
·Power Generation: High-pressure steam cycles and power plant auxiliary systems.
·Offshore Engineering: Offshore platforms and piping systems requiring high resistance to mechanical stress.