The difference between WNRF flange and SORF flange?
WNRF (Weld Neck Raised Face) flange and SORF (Slip On Raised Face) flange are the two most commonly used flanges in industrial pipelines, with the core differences being the connection method, structural strength, and applicable working conditions.
1, Core Definition and Structure
1. WNRF (with neck welding flange)
Full name: Weld Neck Raised Face
Structure: Equipped with a high and long conical neck, the inner diameter of the neck matches the inner diameter of the pipeline perfectly, and the end is beveled.
Connection: Butt weld with the pipeline to form a circular butt weld.
2. SORF (with neck flat welding flange)
Full name: Slip On Raised Face
Structure: The neck is short and short, and the diameter of the flange inner hole is larger than the outer diameter of the pipeline.
Connection: The pipeline is directly inserted into the inner hole of the flange and fixed with a fillet weld on both the outer and inner sides.
2, Key Differences Comparison
| Comparison item | WNRF flange | SORF flange |
| welding method | Butt Weld: The pipeline is connected to the flange groove with a single weld seam | Fillet Weld pipe insertion, with one fillet weld on the inside and one on the outside |
| structural strength | Extremely high neck dispersed stress, resistant to fatigue, vibration, and high pressure | Moderate stress is concentrated at the welding point, resulting in poor fatigue resistance |
| Pressure Applicable | High pressure, high temperature, alternating load Class 150~2500+ | Medium and low pressure, normal temperature usually ≤ Class 600~900 |
| Fluid state of the medium | Smooth and consistent inner diameter, without turbulence or scouring dead corners | Turbulent pipeline shrinks in, and the medium is prone to scouring the inner weld seam |
| detection | Easy to detect butt welds can be subjected to radiographic testing (RT) for quality inspection | Difficult to detect fillet welds cannot be effectively inspected, and internal defects are difficult to detect |
| install | Complex requires precise alignment and high technical requirements for welders | Easy to align, easy to weld, fast installation speed |
| cost | High consumables, complex processing, and high labor costs | Low consumables, easy processing, and low labor costs |
| Applicable scenarios | Petrochemical industry, power plants, steam, long-distance pipelines, critical operating conditions | General cooling water, air, oil, non critical working conditions |
