Development and Qualification of an Additively Manufactured Mechanical Repair Clamp

The growing need for rapid, cost effective repair of high pressure oil and gas infrastructure has driven the exploration of additive manufacturing (AM) for critical load bearing components. This work presents the design, wire arc additive manufacturing (WAAM) production, and qualification of an 18 inch mechanical clamp intended to restore a T section blow down line. The clamp is fabricated from stainless steel using a high deposition rate WAAM process, which enables near net shape geometry, minimal material waste, and the incorporation of complex design features that are impractical with conventional machining.
Design optimization focused on uniform clamping force and accommodation of the T junction geometry while remaining compatible with the existing pipeline. All manufacturing steps were performed in strict compliance with DNV ST B203 “Requirements for the Qualification of Additively Manufactured Metallic Components” and API 20S “Additive Manufacturing of Metallic Materials.” To verify integrity, a sacrificial clamp identical in material, geometry, and process was produced for a full scale hydrostatic pressure test. Post test nondestructive evaluation (ultrasonic C scan, dye penetrant inspection) revealed no cracks, delamination, or leakage, while mechanical testing was seen satisfying both DNV and API criteria.
The successful demonstration highlights the advantages of WAAM for mechanical clamps: significant cost reduction through material efficiency, lead time compression owing to on site or near site fabrication, and design flexibility that permits tailored clamp geometries for complex T section repairs. This approach establishes a viable pathway for rapid, standards compliant remediation of high pressure blow down lines, delivering operational resilience and lifecycle savings.