Pipe Fittings & Flanges
Weld Neck Flange (ASME B16.5)
Weld neck flanges to ASME B16.5 / EN 1092-1 - the long tapered hub gives the best joint integrity for high pressure and temperature and for cyclic service, where fatigue strength and stress transfer beat every other flange type.
Specifications
- Type
- Weld Neck (WN) - long tapered hub
- Size Range
- 1/2-24 inch
- Pressure Class
- Class 150 and 300 stocked, 600-2500 on request
- Facings
- RF standard; FF / M-F / T-G negotiable; RTJ for Class 600+
- Materials
- ASTM A182 F304/304L, F316/316L, F321, duplex F51/F53, F44 (254 SMO) and nickel alloys.
- Standards
- ASME B16.5, EN 1092-1, GB/T 9124, JIS B2220
Product Overview
The weld neck flange carries a long tapered hub that transfers stress gradually from the pipe into the flange, making it the strongest standard flange joint and the usual choice where pressure, temperature or cyclic loading is high. Because the butt weld can be radiographed, it is also the type specified when weld inspection is required.
When to Specify Weld Neck
Choose WN for high-pressure and high-temperature line classes, for systems subject to repeated thermal or mechanical cycling, and wherever the flange weld must be radiographed or ultrasonically tested. The bore matches the pipe schedule, so the joint is a true butt weld rather than a fillet.
Specifications and Standards
Weld neck flanges in 1/2-24 inch to ASME B16.5, EN 1092-1, GB/T 9124 and JIS B2220. Class 150 and 300 are stocked; 600-2500 are made on request. The raised face is standard, with FF, M/F, T/G and RTJ (Class 600 and above) negotiable; RF roughness 125-250 AARH. Materials ASTM A182 F304/304L, F316/316L, F321, duplex F51/F53, F44 (254 SMO) and nickel alloys. The bore is machined to match your pipe schedule so the joint is a true butt weld.
Ordering Information
Send size, pressure class, facing and material grade to melinda@spai-steel.com - flange drilling is coordinated with the pipe schedule and valve class in the same package.