Welding neck flange

Product Overview

Welding‑neck flanges (WN flanges) are high‑performance, heavy‑duty pipe fittings suitable for a wide range of critical industrial piping systems. Featuring a long conical neck, they are fully welded to the pipe, creating a smooth transition that significantly reduces stress concentrations. This design offers high structural strength, excellent fatigue resistance, and reliable, leak‑tight sealing, making it ideal for applications involving high pressure, elevated temperatures, and severe vibration.

Core Parameters

Surface Treatment and Quality Control

Optional coating
Anti-corrosion paints, hot-dip galvanizing, electroplating, and custom anti-corrosion treatment processes tailored for harsh operating conditions.
Quality Inspection Items
Chemical composition analysis, mechanical property testing, metallographic examination, hydrogen‑induced cracking and sulfide stress corrosion testing, heat‑treatment verification, ultrasonic testing (UT), penetrant testing (PT), magnetic particle testing (MT), radiographic testing (RT), hydrostatic pressure testing, and shot blasting; specialized tests can be customized to meet customer requirements.
Welding Quality Assurance
The weld strength shall be no less than that of the base metal, with a smooth weld surface free of defects (such as burn-through, porosity, slag inclusions, and undercut), and a weld reinforcement not exceeding 2 mm.

Application scenarios

Widely used in new construction and maintenance projects across the petrochemical, natural gas, power, nuclear power, offshore platform, shipbuilding, water supply and drainage, urban infrastructure, and district heating sectors. Particularly recommended for critical piping systems that demand stringent safety and tight‑sealing performance.

Customized Services

Our company offers one-stop customized solutions:
Customization is available to meet customer drawings and technical specifications, including non-standard dimensions, special pressure ratings, and various sealing face configurations.
We also offer custom options for specialty materials, dedicated anti-corrosion coatings, product marking and engraving, and exclusive packaging, along with third-party testing services, to meet the personalized requirements of diverse projects.