Enhancement of tubesheet integrity and longevity via GTAW cladding: Experimental assessment and inspection methods

Shell and tube heat exchanger’s reliability and operational safety rely much more on the integrity of the tube to tubesheet (TTS) joint that can be ruined by different factors likes corrosion, erosion, and mechanical stresses. To counter such failures, cladding techniques are employed to deposit a metallic layer protective improving in corrosion resistance of the joint performance at reduced cost. Therefore, this study aimed at investigating the application of Gas Tungsten Arc Welding (GTAW) 10 mm cladding on 50 mm thickness carbon steel (CS) tubesheet (SA 516 Gr.70 N) with outer diameter stainless steel tubes (SA 213 TP 304 L) of 19.05 mm. A total of ten samples were then prepared and the resulting joint quality was evaluated using multiple methods of inspection with reference to ASME Section IX QW 193.1–191.3 standards. These included visual inspection, liquid penetrant testing, macroscopic examination. Additionally, hardness measurements, ferrite testing, and chemical composition analysis were carried out to ensure the quality and integrity of the TTS joints. It is seen from this experimental evidence that cladding achieved via GTAW replicates better joint quality, mechanical integrity, and corrosion resistance for the TTS welds. These findings suggest that using GTAW cladding tends to improve the performance improvement and leak tightness of the tubesheet joints, which ensures their reliable operation and extended joint integrity in various industrial applications. This study reiterates the need for proper cladding techniques and thorough inspection protocols for optimal performances and longevity in keeping critical heat exchanger components well.