Aquam pura / excelsum puritatem aqua curatio ratio est quaedam ratio ad consequi ad aqua purificans per varias aqua curatio processibus et aqua qualitas magna ratio. As per the users' different requirements of the purity of the water, we combine and permute the pretreatment, reverse osmosis and mixed bed ion exchange (or EDI electric desalting unit) to make a set of pure water treatment equipment, moreover, all the water tanks in the system are equipped with liquid level control system, and the pumps are equipped with pressure protection device, on-line water quality detection and control instrument and PLC programmable controller are applied for the whole system ut in armis currit nihil labor in officium.