Reliability and optimal replacement interval of flexible hose assemblies in drinking water installations

摘要

The paper presents theoretical considerations and questionnaire examinations concerning reliability and replacement interval of flexible hose assemblies for washbasins, sinks and water closets. The topic is vitally important for providing home safety. The impact of operational temperature on durability of elastomeric tube was theoretically assessed. Questionnaire examinations covered 356 hoses installed in a block of flats in Poznan (Poland) and detached houses. The analyzed period of hoses' operation was 11 years or less in the case of earlier failure. During that time 41 hoses (approximately 12%) had failed. Reliability functions were obtained separately for cold and hot water installations. It was found that flexible hose assemblies for hot water were less reliable than those for cold water. The optimal time to replace hoses was estimated as 6-7 years.