The importance of flushing and cleaning a closed water system.
Pre-commission cleaning is the process of flushing and cleaning a closed water system, such as those found in heating, cooling, or industrial processes, and bringing it to a satisfactory state prior to Commissioning. By preventing corrosion and scaling, we can maximise efficiencies and ensure longevity of a system.
Here are six reasons why flushing & cleaning of closed water systems is carried out:
1. Removal of Debris: During installation closed water systems can accumulate various types of debris, including dirt, sediment, rust particles, and construction residues. Flushing removes these contaminants, which can otherwise accumulate and cause blockages or impair the system’s performance.
2. Prevention of Corrosion: Corrosion is a significant issue in closed water systems, as it can lead to equipment damage, leaks, and reduced efficiency. Flushing will remove particulates that can settle out in low flow areas and by using biocides we are able to combat bacteria which can lead to corrosion. In closed systems, the rate of corrosion of steel is minimised by the use of chemical corrosion inhibitors, lowering dissolved oxygen levels, raising the pH of the water and avoidance of stagnation.
3. Scale Control: Scaling occurs when minerals and other dissolved substances precipitate and form deposits on the surfaces of pipes, heat exchangers, and other system components. By flushing & cleaning we can remove these deposits and with the addition of inhibitors are able to reduce the concentration of scaling agents in the water.
4. Biofilm and Microbial Control: Closed water systems can be susceptible to the growth of microorganisms, which can form biofilms. Biofilms not only reduce heat transfer efficiency but also contribute to fouling and can lead to microbiological induced corrosion (MIC). By flushing and using appropriate biocides we can control microbial growth and minimise the formation of biofilms.
5. Efficiency and Performance: A clean water system operates more efficiently than a system with accumulated debris, corrosion, or scaling. The cleaning process will help to achieve design, ensuring optimal heat transfer, reducing energy consumption, and maintaining the desired system performance.
6. System Longevity: Flushing & cleaning closed water systems contribute to their long-term durability and longevity. By preventing corrosion, scaling, and microbial growth, the risk of equipment failure, leaks, and premature replacement is minimised, resulting in extended system lifespan. With constrained budgets, coupled with an uncertain economic outlook extending the longevity of critical assets has never been so important.
The Guidelines and standards that are followed are:
- BSRIA BG-29 – Pre Commission Cleaning of Pipework Systems.
- BSRIA BG-50 – Water Treatment for Closed Cooling and Heating Systems.
- British Standard BS 8552 – Sampling and monitoring of water from building services closed systems.
ph Water & Air Technologies have succesfully provided pre-commission cleaning services at some of the largest and most prestigeous projects in the UK. It is important to note that flushing and cleaning procedures can vary depending on the specific type of closed water system, the water quality, and the type of contaminants present.
Graeme Stevens WMSoC | Director