3D 5D Radius Long Sweep Butt Weld Fittings Seamless Bend 316L SCH40 EN 10253-2
When a line must minimize pressure loss, turbulence, or erosion, engineers specify long sweep bends rather than standard fittings. These 3D and 5D radius butt weld fittings provide gently curved transitions that maintain smooth flow and reduce energy loss at every directional change.
Formed from seamless pipe through bending and heat treatment processes, these long sweep butt weld fittings maintain consistent wall thickness throughout the entire arc. Available in 3D, 5D, and custom radii, these seamless 316L bends are ideal for slurry systems, pneumatic conveying, and high-purity lines where tight elbows would cause turbulence or premature wear.
Each long sweep bend is manufactured to EN 10253-2 and ASME B16.9 standards, with tangent lengths and radii precisely machined to match your spool drawings. The 316L stainless steel undergoes solution annealing and pickling to ensure a clean, corrosion-resistant bore.
The seamless construction eliminates weld seams, providing superior resistance to corrosive media and cyclic loading compared to fabricated bends. Available in 304L, 316L, duplex, and nickel alloys to match your specific pipe material requirements.
Technical Specifications
| Material Grade |
316L / 1.4404 (also 304L, duplex, nickel alloy) |
| Product Type |
3D / 5D Long Radius Bend |
| Bend Radius |
R=3.0D, R=5.0D and custom |
| Size Range |
DN25 - DN600 |
| Wall Thickness |
SCH10 - SCH160 |
| Standards |
EN 10253-2 / ASME B16.9 |
| Surface Finish |
Pickled and Passivated |
| End Connection |
Butt Weld (BW) |
Key Advantages
- Large radius design reduces pressure loss, noise, and erosion in pipeline systems
- Seamless construction eliminates weld seams for enhanced corrosion resistance
- Consistent wall thickness throughout the arc ensures reliable weld quality
- Solution annealing and pickling provide a clean, hygienic bore surface
- Manufactured to EN 10253-2 and ASME B16.9 standards with custom radii available
- Ideal for slurry, pneumatic conveying, and high-purity applications
Typical Applications
- Slurry and mining transport lines
- Pneumatic conveying systems
- Food, dairy, and pharmaceutical process lines
- HVAC and large air ducting systems
- Pulp and paper stock lines
Every Long Sweep Butt Weld Fitting is packed in seaworthy wooden cases or pallets with protective end caps. We offer customized marking and labeling, and can consolidate mixed sizes in single shipments to reduce freight costs and handling time.
As a manufacturer, we support custom sizes, wall thicknesses, and materials, and can arrange third-party inspections (SGS, BV, or TUV) upon request. Our engineering team reviews every inquiry to recommend materials, wall thicknesses, and standards that best match your pressure, temperature, and corrosion requirements.
Each order undergoes dimensional inspection against applicable standards before dispatch, with quality records retained for potential re-testing. We welcome factory audits and pre-shipment inspections, and can supply reference projects and test reports to support tender documentation.
Frequently Asked Questions
What is the difference between a 3D and a 5D bend?
The number indicates the centerline radius in pipe diameters. A 3D bend curves over three diameters, while a 5D bend curves over five diameters. The 5D radius butt weld fitting provides the smoothest flow with the lowest pressure loss.
Are these long sweep bends seamless?
Yes. These seamless 316L bends are formed from pipe without longitudinal welds, making them particularly suitable for corrosive and high-purity service applications.
Can you produce to my spool drawing?
Yes. We machine tangent lengths and radii to match your drawings and work to EN 10253-2, ASME B16.9, or custom specifications as required.
Which materials are available?
Long sweep butt weld fittings are available in 304L, 316L, duplex 2205, super duplex, and various nickel alloys to meet diverse application requirements.
