What are the key points of boiler cleaning and descaling

Temporary system pressure: during the pressure process, all welded joints should be carefully checked to ensure that there is no danger. Ammonia hydrogen fluoride is needed in the pickling process, so the tightness and corrosion resistance of welded joint are higher than that of hydrochloric acid pickling.

Water washing: after the pickling of water wall system, it is recommended to close the vacuum discharge of the drain valve, open the drain valve after the water is full, and finally maintain the continuous cleaning of steam level. Compared with the method of no acid discharge and direct drainage, this method can save time, and it is not easy to produce secondary corrosion and the cleaning effect can be fully guaranteed.

Passivation liquid discharge: when the pump discharge is stopped, maintain the high water level of the steam drum, first open the recycle valve of the economizer, the accident discharge valve of the steam drum, the continuous discharge valve, the fixed discharge valve, the heating valves of the furnace, and the drain discharge valve, and then discharge the passivation liquid in the economizer and the water wall after a certain period of time. In this way, it can ensure that the valve core is not easy to be corroded by peeling off in the pickling process after the valve is washed with pressure.