آنالیز ایمنی جوشکاری در پالایشگاه تهران و اثر بخشی راه های کنترلی

The safety of high risk jobs especially in oil refining activities is a major concern. In the present paper, the welding risks in Tehran oil refinery have been assessed using the Job Safety Analysis (JSA) and the effectiveness of the controlling methods have been investigated. A descriptive study was conducted on 33 risks of 10 welding tasks in Tehran oil refinery (north unit). After arranging the appropriate expertise team, tasks in the welding process were identified using two methods of viewing the process and interviewing with the welders. The risks of each task were then identified through viewing the process, interviewing the welders and completing safety checklists. Risk Priority Number (RPN) was used for risk assessment. RPN was estimated from Likelihood and Severity Numbers using Australia/New Zealand standard (AS/NZS 4360/2004). Risk assessment was conducted for existing and post-control conditions. The effectiveness of the controlling measures suggested by the expertise team was evaluated using appropriate statistical methods. The results revealed that in the existing condition, 27.3% of the studied risks have a RPN of 5 (with an extremely high hazard potential), 3% a RPN of 4 (with a high hazard potential) and 69.7% with a RPN of 3 (with a medium hazard potential). The results also revealed that with the application of control measures suggested by the expertise team, 21.2% of the studied risks will hold a RPN of 4 (with a high hazard potential), 6.1% will have a RPN of 3 (with a medium hazard potential), 48.5% with a RPN of 2 (with low hazard potential) and 18.2% will have a RPN of 1 (with a negligible hazard potential). Statistical tests revealed that the application of control measures, will reduce the average amount of likelihood, severity and risk priority numbers significantly (Pvalue<0.01).