Welding neck flanges are the flange type with the highest connection strength and most reasonable stress distribution in piping systems. Featuring a tapered hub that enables butt welding with pipes, they significantly enhance root strength. The nickel alloy welding neck flanges supplied by Hefei Tailan Metal Co., Ltd. are manufactured from high-quality nickel-based alloy forgings through multiple precision processes including forging, solution heat treatment, machining, drilling, and pickling/polishing. Featuring reasonable hub transition, smooth sealing surface, high strength, and excellent corrosion resistance, they are specifically designed for pipe connections under demanding conditions such as high temperature, high pressure, and severe corrosion.
Supply Range
Nominal Diameter (DN/NPS): DN15 – DN600 (1/2 inch – 24 inches); Larger diameters negotiable
Pressure Class: Class 150, 300, 600, 900, 1500, 2500 (ASME)
Facing Type: Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ)
Flange Type: Welding Neck, Long Welding Neck (LWN)
Machining Precision: Sealing surface roughness Ra 3.2μm – 6.3μm (as per standard requirements)
Hub Transition: Tapered hub, bevel preparation matching pipe
Surface Condition: Machined, Pickled, Polished optional
Marking Method Steel stamp marking on flange outer edge, conforming to MSS SP-25 or customer requirements
Strict Non-Destructive Testing
Every nickel alloy welding neck flange undergoes rigorous NDT inspection:
- Penetrant Testing (PT) : Detecting surface-opening defects, conforming to ASTM E165 standard
- Ultrasonic Testing (UT) : Detecting internal defects, conforming to ASTM A388 standard
- Hardness Testing: Verifying heat treatment effectiveness and mechanical property uniformity
Multiple Facing Types Available
Various facing types available according to service conditions:
Raised Face (RF) : Most common, suitable for Class 150-2500
Ring Type Joint (RTJ) : For high pressure, high temperature, strict leakage prevention
Flat Face (FF) : For cast iron flanges or low pressure conditions
Stock Availability, Emergency Response
We maintain inventory of flange blanks for mainstream grades such as Inconel 600/625, Monel 400, and Hastelloy C-276. Orders can be quickly arranged for machining, meeting customer needs for emergency repairs and short-lead-time projects.
