我市某县一个林场使用一台KZL1—8一A_2型水火管组合蒸汽锅炉,共运行不足两个生产周期近十个月的时间,于一九八六年三月发现锅壳下部着火处产生裂纹漏水堵汽。经检查发现距前管板730毫米处产生一环向裂纹,可见长度50毫米。裂纹呈细直线状,贯穿性,裂纹开口宽0.4毫米,裂纹周围金属光洁、色泽正常,且未发现其他裂纹。进入锅筒内检查发现排 A forestry plant in a county of our city used a KZL1-8 A-2 water-steam combined steam boiler for a total of less than two production cycles for nearly ten months. In March 1986, it was found that the lower part of the shell was exposed to fire Crack water leakage blocking steam. The inspection found that there was a circumferential crack at 730 mm from the front tube plate, showing a length of 50 mm. Crack was thin straight through, the crack opening width of 0.4 mm, crack around the metal smooth, normal color, and found no other cracks. Into the drum tube inspection found row