1. In standard piping codes like ASME B31.1, ASME B31.3, or API standards, fabricating a 45-degree elbow from a 90-degree elbow is
not permitted as a standard practice. Cutting a 90° elbow into two 45° elbows alters the geometry, wall-thickness distribution, stress
distribution, and structural integrity. Manufacturer certifications apply to the original component. Altering it voids the warranty and makes
traceability difficult. However, in rare cases, for low-pressure/non-critical services and non-code applications, it may be accepted with
engineering approval. If required, fabricate from the pipe.
2. However, the following quality and inspection requirements must be met to ensure safety and compliance. Ensure the material retains its required hardness and toughness after cutting. PWHT may be required if the process affects material properties. The resulting 45° bend must match the specified long-radius (LR) or short-radius (SR) elbow dimensions as per ASME B16.9 or project specs. Ensure no excessive thinning occurs at the cut edges. Measure wall thickness at critical points.
3. If the elbow is cut and reassembled, the bevel angle, root face, and gap must comply with the WPS. Clearly mark the modified fitting with material grade, heat number, and unique ID. Document the entire process, including cutting method, welding parameters, NDE results, and final dimensional checks. Always obtain written approval from the project engineer before proceeding.
C Sridhar.
Hi,Please check your project specifications of the 45 degree elbow., like cast, welded, forged. I believe you should take approval from your project manager/end user.
Regards,Mr. Harish.--
On Fri, 6 Nov 2026 at 11:06, Mahmood Alhinai <mahmood.m.alhinai@gmail.com> wrote:
Dear expert,--
Due to shortage of 45 elbow, fabrication crew want to fabricate 45 elbow from 90 elbow.
1) Is it allowed?2) From quality aspects, what are the requirements to approve?
Thanks
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