Quality inspection of ASME B16.9 seamed and seamless long radius elbows ordered by British customers
When delivering critical carbon steel pipe fittings to international clients, especially for large-scale infrastructure projects, product quality and compliance with technical standards are non-negotiable. Haihao Group, a leading manufacturer of steel fittings in China, recently completed a high-spec order of ASME B16.9 long radius elbows for a UK-based client. This batch included both welded and seamless elbows in large sizes, with tailored inspection processes for each type to ensure full conformity.
90 Degree LR Elbows produced by Haihao Group
Quality inspection product list：ASME B16.9 A234 WPB LR Elbows
| Elbow Type | Standard | Material | Sizes |
| Welded Long Radius Elbows | ASME B16.9 | ASTM A234 WPB | 32″, 36″, 40″ |
| Seamless Long Radius Elbows | ASME B16.9 | ASTM A234 WPB | 16″, 20″, 24″ |
These elbows were produced as long radius (1.5D) elbows, commonly used in high-flow industrial pipeline systems where smoother direction changes and minimal pressure drop are critical.
Bending angle detection
Inspection Differences Of Seamless And Welded Elbows
The inspection requirements differ significantly between seamless and welded elbows due to the presence of a weld seam in the latter, which introduces additional quality risks and thus requires additional nondestructive testing (NDT).
1.Common Inspection Items (Both Types):
1.1Dimensional Inspection:
Outer diameter (OD)
Center-to-end length
Wall thickness (measured at multiple locations)
1.2.Bevel End Verification:
Angle accuracy (typically 37.5° ± 2.5°)
Smoothness for weld fit-up
1.3.Material Identification:
Heat number verification
3.1 MTC certificate review (per EN 10204)
1.4.Visual Surface Examination:
Check for surface defects such as cracks, dents, corrosion, or lamination
2.Additional Inspection for Welded Elbows:
Unlike seamless elbows, welded elbows contain a longitudinal weld seam, which represents a potential weak point if not properly inspected and qualified. Therefore, Haihao applies the following additional quality checks for welded elbows:
Ultrasonic wall thickness testing of ASME B16.9 long radius elbow
2.1. Weld Seam Nondestructive Testing (NDT):
100% Visual Examination (VT) of the weld seam for alignment, undercut, or surface porosity
100% Radiographic Testing (RT) or Ultrasonic Testing (UT) based on client request or code requirement
RT performed per ASME Section V standards
Acceptance criteria according to ASME B31.3 or project specification
2.2. Weld Profile and Quality:
Consistent bead appearance and penetration
No excessive reinforcement or undercut
Smooth transition between base metal and weld
2.3. Weld Heat-Affected Zone (HAZ) Thickness Check:
Ensure minimal wall thinning or distortion around the HAZ
On-Site Inspection Photos & Documentation
Haihao Group’s QC engineers documented each stage of inspection for client verification. For the UK order, full inspection reports, dimension charts, and NDT result sheets were provided, along with photos showing:
Large-diameter elbows (stacked and marked)
Wall thickness measurements with calibrated ultrasonic gauges
Bevel inspection using templates
Radiographic film interpretations (for welded elbows)
All items were tagged with order reference and heat number, and securely packed in wooden crates with moisture barrier lining for ocean shipment.
Project Application & Customer Assurance
The elbows in this order are intended for use in power station infrastructure in the UK, requiring both high-pressure resistance and longevity under cyclic thermal loads. The use of A234 WPB carbon steel ensures excellent weldability and mechanical strength across the operating temperature range.
By providing both welded and seamless options, Haihao enabled the client to optimize material use—utilizing seamless elbows for high-stress segments and welded elbows where structural demands were moderate but size availability critical.
Why Choose Haihao Group?
- Over 40 years of production experience in carbon steel elbows and pipe fittings
- Full range of ASME B16.9 fittings, including elbows, tees, reducers, caps
- In-house NDT lab with RT, UT, MT, PT capabilities
- Welders and inspectors certified to ASME IX and EN ISO 9712
- Products exported to over 80 countries, with strong presence in Europe, Middle East, and Southeast Asia
Contact Haihao Group for Custom Fitting Solutions
Looking for a reliable supplier of large-diameter ASME B16.9 elbows with full QA documentation? Haihao Group delivers with technical precision and global logistics experience. Email:sales@haihaogroup.com