Circulating water pre-film formation step

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1. Water flushing: Water is introduced into the reservoirs and pipelines of the circulating water system. Once the water level in the reservoir reaches the safe level, the valves for the inlet and outlet pipes of the circulating water are opened, and all the valves of the heat exchangers in the system are also opened. The circulating water pump is then started to flush the entire system; during this process, the flow rate should be maintained at above 1.0 m/s, with 1.5 m/s being even better. The flushing time is 2 to 4 hours. During the water flushing period, the operators of various systems conduct thorough inspections of the different components of the circulating water system; any leakage points detected must be reported immediately, and the maintenance staff should take action to seal those leaks right away. 2. If possible, the water can be drained such that its turbidity is less than 10 NTU. 3. Sodium hypochlorite or other specialized descaling and disinfecting agents are used to remove sludge and disinfect the system ； Ensure that the residual chlorine level remains above 1.0 ppm during this period, with circulation lasting 24–48 hours. Operators must wear protective equipment such as masks and gloves when adding chemicals like cleaning agents, and be careful to ensure safety during the addition process. 4. If possible, the water can be drained to a turbidity of less than 10 NTU ； 5. Add corrosion inhibitors to protect the system. 6. Add organic acids such as citric acid or specialized acidic cleaning agents; once it is confirmed that these chemicals have been evenly distributed throughout the system, monitor the pH value and keep it within the range of 4.5–5.5. During this process, monitor the pH value, turbidity, total iron content, and calcium ion levels. The cleaning process is completed once the concentrations of total iron and calcium ions stop increasing. Based on experience, it takes about 48-72 hours. 7. Drain the water until it reaches normal levels. 8. After cleaning, it is advisable to carry out a pre-coating treatment to reduce the workload related to water treatment during regular operation. 9. Depending on the type of circulating water system and the types of pollutants that accumulate, different cleaning procedures are required. In general, these are the steps mentioned above; however, the specific concentrations of chemicals used depend on the conditions of the system. Pre-coating performance: KBei-831 is a mixture composed of polyphosphates and zinc salts, among other components. Its solution can form a protective film on the metal surface in a short period of time. Purpose: Suitable for pre-coating heat exchangers and pipelines made of materials such as carbon steel, copper, and stainless steel in circulating cooling water systems. Pre-coating with this product can **improve the corrosion inhibition capacity of the equipment. Conditions and manufacturing methods: Turbidity: ≤10mg/L; pH value: 5.5–6.5; Temperature: room temperature; Time: 24–48 hours. Performance: The pre-coating agent was developed to provide corrosion protection before new equipment is put into use and when the equipment is not in operation. Practice has shown that corrosion occurs much more severely on some equipment after it is temporarily shut down compared to when it is in operation. Therefore, anti-corrosion treatment at shutdown is highly necessary. Pre-coating agents have advantages such as easy technical mastery, time and labor savings, simplicity of use, and convenience in operation. Compared to similar pre-coating agents, in addition to its ability to form an anti-corrosion film on carbon steel, stainless steel, and copper surfaces within 48 hours, it only needs to be evenly added to the water poured into the equipment during use. Usage: Add under the guidance of technical personnel. The monitoring of pre-coated films generally involves the use of a test strip method; after pre-coating, a uniform colored film can be seen with the naked eye on the test strip, and there is no sign of rust.