To reduce the risk of bacterial development healthcare facilities must produce and distribute hot water at high temperatures, according to the HSE Approved Code of Practice and Guidance document, HSG274.
However, Delabie, points out, scalding risk increases considerably for hospital patients. The company said: “In healthcare facilities this risk is particularly high for the elderly and people with slower reflexes.”
According to RoSPA data, every year in the UK 600 people suffer severe scald injuries that are wholly avoidable. It is therefore essential to maintain a maximum temperature that reduces the risk of scalding and provides safety features at point-of-use outlets. “HSG guidelines state that where a significant risk of scalding has been identified, thermostatic mixing valves should be considered for baths and showers to deliver water at safe temperatures,” Delabie explained. “For all other applications, a pressure-balancing mixer will deliver all the same benefits without the thermostatic element.
“A mixer with a pressure-balancing cartridge maintains a constant pressure between the hot and cold water, avoiding temperature variations due to pressure changes in the system. This provides an alternative to thermostatic technology, which regulates the temperature via a thermostatic cell.
“If the cold water supply pressure drops unexpectedly, the hot water will shut off immediately, with only a slight trickle remaining. Similarly, if the hot water pressure fails, the cold water will also shut off. This avoids the risk of cold showers – which are uncomfortable, and may even result in the user losing their balance. As an additional safeguard, some mixers are supplied with a maximum temperature limiter. The temperature limiter is usually preset, but it may be adjusted by the installer. The user cannot increase the temperature above the temperature limit, preventing any risk of scalding.
A key factor in the development of Legionella spp. bacteria is standing water at temperatures between 20 and 46°C. Pressure-balancing mixers feature a single mechanism which controls both flow and temperature. The water circulates from the inlet to the mechanism inside narrow copper tubes. Delabie said: “These have a two-fold benefit; the volume of standing water is minimised, and when the water flows, its passage is accelerated. Both these factors help to minimise the development of biofilm which provides shelter and a source of nutrients for bacteria such as Legionella spp.
Delabie points out that brass mixers and taps have rough cast interiors with ‘niches’ that form during the casting process, where bacteria can adhere. Delabie mixers and taps have completely smooth interiors, contributing to the rapid passage of water, and reducing bacterial development.
The company says its ‘new generation’ of pressure-balancing mixers are ‘ideal for use in healthcare facilities, where the risk of contamination by Legionella spp. bacteria must be balanced against the risk of scalding’. They deliver anti-scalding safety and also help to reduce bacterial development.
