Leading China factory and suppliers of ASME B16.5 and B16.47 Slip On Flanges. Offering Class 150 to 2500 in ASTM A105 carbon steel, A182 F304/F316 stainless, and A350 LF2 alloy steel for industrial piping systems.
The Slip-On Flange (SO) according to ANSI/ASME B16.5 is a critical structural metal component designed for seamless integration into piping systems. Engineered for versatility and ease of installation, these flanges slide over the pipe and are secured with fillet welds on both the inner and outer surfaces, providing a reliable seal for a wide range of industrial fluid transport applications.
Manufactured from high-grade carbon steel, stainless steel, and alloy steel, our SO flanges ensure exceptional durability and corrosion resistance. By adhering to rigorous ASME B16.5 and B16.47 standards, we provide precision-engineered solutions that balance cost-efficiency with high mechanical performance, making them ideal for low to medium pressure systems across the oil, gas, and chemical sectors.
| Executive Standards | ANSI/ASME B16.5 (Class 150-2500), ASME B16.47 (Class 75-900) | Nominal Pipe Size | 1/2" (15mm) to 60" (1500mm) |
|---|---|---|---|
| Pressure Ratings | Class 150 (PN2.0MPa) to Class 2500 | Material Options | ASTM A105, A182 F304/F316, A350 LF2 |
| Sealing Face Types | Flat Face (FF), Raised Face (RF), MFM, Tongue-Groove (TG) | Thickness (NPS 4") | Class 150: 12.7mm | Class 300: 19.1mm |
| Temperature Range | Carbon Steel: -29℃ to 427℃ | Stainless: up to 870℃ | Machining Tolerance | Flatness ≤0.05mm/m | Hole Position ±0.3mm |
| Testing Protocols | 100% MT for neck welds, UT for Class 1500, Hydrostatic Test | Thread Standard | ASME B1.1 Unified National Coarse (UNC) |
Using ASTM A182 F304/F316 stainless steel ensures stability in pH 2-12 environments and seawater treatment systems.
The slip-on design allows for faster alignment and simpler outer fillet welding compared to weld-neck types.
Alloy Steel (A350 LF2) provides excellent impact energy (≥27J at -46℃) for LNG and liquid nitrogen pipelines.
Advanced CNC processing ensures extreme flatness and precise bolt circle diameters for leak-proof sealing.
100% Magnetic Particle and Ultrasonic testing eliminates internal defects and welding cracks.
Reduced material usage and simplified processing make SO flanges the economical choice for Class 600 and below.
Spectral analysis to verify Cr/Ni content and material grade before production.
Open die forging for NPS ≤12" to ensure no folding defects in the flange neck.
Normalization at 890-920℃ for carbon steel to eliminate welding stress.
Real-time monitoring of sealing face flatness and bolt hole positional tolerance.
Integrated MT and UT inspection platforms for high-pressure safety certification.
Hydrostatic testing at 1.5x design pressure with 30-minute leak-free holding.
| Comparison Index | Slip-On Flange (SO) | Weld Neck Flange (WN) |
|---|---|---|
| Welding Difficulty | Low (Outer Fillet Weld) | High (Full Penetration Groove) |
| Applicable Pressure | ≤ Class 600 (PN11MPa) | Up to Class 2500 |
| Material & Process Cost | Low (Efficient Production) | High (Complex Neck Structure) |
| Sealing Performance | Medium (Gasket Dependent) | High (Fused Pipe Connection) |
| Typical Application | Water/Air Systems | High-Pressure Oil & Gas |
Slip-On flanges slide over the pipe and use fillet welds, offering lower costs and easier installation, whereas Weld Neck flanges are butt-welded for higher pressure and temperature resistance.
Stainless Steel (ASTM A182 F304/F316) is highly recommended due to its Cr-Ni alloy composition, which resists acid and alkali corrosion across a pH range of 2 to 12.
We employ 100% Magnetic Particle Testing (MT) for neck welds and Ultrasonic Testing (UT) for Class 1500 flanges, combined with hydrostatic pressure tests at 1.5x design pressure.
Yes, provided they are manufactured from Alloy Steel (ASTM A350 LF2), which offers the necessary low-temperature toughness (impact energy ≥27J at -46℃).
Common types include Flat Face (FF) and Raised Face (RF). For Class 600 and above, Male-Female (MFM) or Tongue-Groove (TG) faces are used to enhance sealing.
We use spectral analysis on raw materials to ensure precise alloy percentages, such as verifying that Chromium content is ≥18% for Grade 304 stainless steel.
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