Maintenance cycle and cleaning steps of PP water tank Maintenance cycle and cleaning steps of plastic water tank. The maintenance cycle of plastic water tanks is generally half a year. During this period, if there is a fault or other special circumstances, the cleaning times can be increased. Cleaning the water tank is very troublesome, because this process determines the quality of water in the water tank, so you must master each process in detail when cleaning the water tank. What are the procedures for cleaning the water tank? Step 1 is to empty the water tank. First close the main water inlet valve, then close the connecting valve between the water tanks, and then open the drain valve to discharge the water in the water tanks. The second step is to vent the gas in the water tank. Because of the use, toxic gas will appear and accumulate in the water tank, so it is necessary to purify the internal air before repairing and maintaining the water tank. The method is to blow air into the water tank for 2 hours with a hair dryer, and then put the burning candle into the water tank to ensure that there is enough air inside. Step 3, maintenance of plastic water tank. After the lighting in the water tank is turned on, the water tank should be repaired and maintained. Usually, the water tank should be cleaned more than 3 times, and the pipes, valves and floats should be maintained as required. Step four, close the water tank. After the water tank is solidified, drain the internal sewage, spray disinfectant water, close the drain valve and inject clean water.