Q. Is water treatment required on sprinkler systems?

A. In an ideal world the water in these systems would be treated. However it is not possible to apply treatment that will have a lasting effect given the static nature of such systems. In the event that a sprinkler system is actually used for a fire the condition of the water becomes of secondary importance.

Q. Why are bacteria a problem in closed water systems?

A. There are many different types of bacteria many of which are harmless. Some bacteria can however cause problems if they get into the wrong place. In closed systems bacteria which cause biofilm are problematic since this biofilm can reduce the efficacy of flushing (leaving debris within pipework), affect thermal transfer, create conditions for under deposit corrosion and, in association with other debris, cause blockages or restrictions in control and regulating valves as well as strainers. Other undesirable bacteria are associated with microbial corrosion or loss of corrosion inhibitor (in the case of nitrite based inhibitors).

Q. Why should domestic water systems be chlorinated?

A. Chlorine (sodium hypochlorite) is an oxidising biocide, which will control microbiological contaminants in domestic water systems. Chlorination is the process of applying sodium hypochlorite to systems to control/kill microbes. Water in domestic systems is used for drinking, washing, cooking and other procedures where personnel come into close contact with the water. It is therefore important to control microbiological conditions in such systems and if problems occur chlorination may be necessary to restore suitable water quality. In addition to chlorine there are other approved products, such as chlorine dioxide, which may be used in domestic systems for the same purpose. The degree of treatment required depends on the nature of the fouling.
It must be noted that some products used to disinfect systems are being left within the pipework after dosing. This is only acceptable if levels comply with those outlined in the DWL list of approved products/water supply (water fittings) regulations 1999.

Q. Why is water quality in closed systems important?

A. Closed water systems are carefully designed to create precise and adaptable environmental conditions within buildings or process plant. The design necessitates the use of small bore control and regulating valves. If corrosion debris, installation debris or sludge are present these small orifices may become blocked and the system will not operate to design parameters. The presence of debris will make microbiological control more difficult. Ultimately if systems are not cared for the pipework and fittings may fail prematurely due to corrosion and other contributory factors. Water quality and water treatment are therefore very important.

Q. Is water treatment required when plastic pipework is being used?

A. Water treatment is required for plastic pipework although the actual processes may be different if there is no mild steel present in the circuit. It is important to ensure that chemicals used are compatible with the plastic in use. Newly installed plastic systems contain particulate matter, which needs to be removed before bringing the system on line. There is a potential for microbiological problems if adequate water treatment is not undertaken. It is very rare to find an entirely plastic system and the selected water treatment for the system needs to be suitable for all the plant, pipework and fittings present.

Q. Why should cooling towers be cleaned?

A. Physical debris which resides within cooling towers can cause operational problems by blocking strainers etc but the major cause for concern is that the debris creates areas where bacteria can replicate. These bacteria may include Legionella which can be a health hazard.