我系统所属单位在用低压蒸汽锅炉共有98台,大部分是山东、天津E级锅炉制造厂的产品。在近几年的使用、检验过程中,发现手孔渗漏现象较为突出。由于手孔的渗漏,使手孔加强圈、手孔盖和锅筒在乎孔下部区域产生严重腐蚀,为此而更换手孔装置的每年占总台数的10%。虽未发生过重大事故,但给用户造成的经济损失不小。造成手孔装置渗漏的原因很多,如在上手孔盖时,密封垫偏移或未上紧等,但主要是由于手孔装置的制造质量引起的。分析原因有二: 1 出现渗漏的这些锅炉的手孔加强圈,一般采用φ108×4mm或φ114×4mm的无缝钢管,切成25～ The units to which my system belongs use a total of 98 units of low-pressure steam boilers, most of which are products from Shandong and Tianjin E-class boiler factories. In recent years, the use of the inspection process, found hand hole leakage is more prominent. Due to the leakage of the hand hole, the hand hole reinforcement ring, the hand hole cover and the drum tube are severely corroded in the lower area of ​​the hole, and the hand hole replacement device is replaced by 10% of the total number each year. Although no major accident has occurred, the economic loss caused to users is not small. Leakage caused by the hand hole device for many reasons, such as the first hole in the cover, the gasket offset or not tight, but mainly due to the quality of manufacturing hand hole device. There are two reasons for the analysis: 1 leakage of the hands of these boilers to strengthen the ring, the general use of φ108 × 4mm or φ114 × 4mm seamless steel pipe, cut into 25 ~