In cutting machines of mining and construction works, water system has an important and critical role. Due to many aspects and reasons, these machines can not work without water. In longwall mining, the drum shearer performance is highly related to its water system. Any problem in water system of shearer leads the machine to stop automatically; therefore, the reliability of this system is very
... [Show full abstract] important in reliability of shearer. In this study, for modeling this system, three subsystems in series network were considered; fi lters, spray jets and hoses & valves. Then, the fi eld data of water system of drum shearer of Tabas Coal Mine has been collected and analyzed using statistical modeling technique. The results showed that fi lters subsystem has the highest reliability importance among the subsystems and is defi ned as the most critical subsystem. In addition, the fi lters, spray jets and hoses reach the reliability of 80% respectively after about 8.5, 23 and 87 hours.