HSG 274 Part 1 Cooling water system monitoring & inspection
A cooling system operator is required to ensure that suitable tests are carried out to demonstrate that the risk of legionella has been controlled.
RWS will ensure you have sufficient understanding of the significance of each test and clearly advise on any actions required.
Why you need water treatment? Maintaining good water quality is essential to the safe and efficient operation of every open evaporative cooling system. All such cooling plant works by evaporating a small portion of the recirculating water and any impurities present remain in the system where their concentration can increase rapidly to reach unacceptable levels. Airborne impurities may also be drawn in and, if impurities and contaminants are not effectively controlled, they can cause scaling, corrosion, biological growth and sludge accumulation. These not only reduce heat transfer efficiency and increase operating costs, but create conditions under which legionella are likely to multiply.
Cooling water system monitoring
The cooling water treatment service visit report is the primary means of communication between RWS (the service provider) and you, the system owner/operator.
It is an essential record of the water conditions prevailing in the system and therefore has legal status, should be signed by the service technician and yourself and retained in a record system for at least five years.
All cooling systems need a specifically-designed water treatment programme, which takes into account factors such as the quality of the make-up water, the equipment cooled and operating patterns. RWS have been providing these programmes for many years, carefully recommending control levels.
Our water treatment programmes include:
- A controlled bleed or blowdown – essential to prevent excessive build-up of dissolved solids and impurities in the recirculating water.
- Biocidal control – essential to prevent or control the growth of algae, slimes and other micro-organisms including legionella.
- Scale and corrosion control – Minimise the quantity of scale and rust. In hard water areas it may be necessary to soften the make-up water to the system.
- Dispersants or sludge control chemicals — reduce sediment, help keep surfaces clean and enable the other water treatment chemicals to work more effectively.
- Suspended solids control – in systems suffering excessive suspended solids, a filter or similar device may need to be fitted (sidestream).
RWS Pre-treatment, Dosing and control equipment.
Good control combined with regular monitoring can deliver excellent waterside conditions, for years.