Series B (API 605) Class 600 Weld Neck (WN) flange is the go-to component for high-pressure gas transmission, petroleum refining, and chemical processing due to its compact bolt pattern and superior pressure retention. HT PIPE supply all different types and scales of flanges. Please feel free to contact us for further product information and pricing.
Why Choose Series B Over Series A?
Series B (API 605): Features smaller, more numerous bolts and a more compact flange outer diameter. It is lighter and more cost-effective for large-scale pipeline projects where space is at a premium.
Series A (MSS SP-44): Larger, heavier, and designed to withstand higher external loading and bending moments.
Technical Insights: Structural Advantages of the WN Flange
1. Stress Distribution Optimization
The WN flange features a long tapered hub. This isn't just a welding transition; it acts as a structural reinforcement that transfers stress from the flange ring to the pipe wall, which is critical under the pressure fluctuations inherent in Class 600 systems.
2. Fatigue Resistance
In environments with high cyclic pressure (such as pump station outlets), the fatigue life of a Weld Neck flange is significantly higher than that of a Slip-on flange.
3. Bore Matching (Bore Size)
When ordering, it is mandatory to specify the pipe wall thickness (Schedule), such as Sch 40, Sch 80, or a specific thickness. The inner diameter of the WN flange must match the pipe's ID to ensure a smooth flow transition and prevent turbulence or erosion.
ASME B16.47 Series B Class 600 WN Flange dimension
