BS 8558:2015 pdf free.Guide to the design,installation, testing and maintenance of services supplying water for domestic use within buildings and their curtilages – Complementary guidance to BS EN 806.
BS 8558 Where the system is receiving water from a public supply the material in contact with the water needs to conform to the Water Fittings Regulations [19], [20] and [21]. Where the water is exclusively provided from a private source, such as a well or borehole, the Private Water Supplies Regulations [15], [16], [17] and [18] apply.
The influence on water quality of the materials used in the construction of the water service installation, and of those in contact with the installation, is
explained in BS 6920 (all parts).
Materials should be selected depending on the present and reasonably foreseeable character of the water supply and its intended use. Information on the character of the water supply is available from the local water supplier.
Internal corrosion leading to premature failure of metal pipes can occur with certain waters. External corrosion of pipes and fittings laid below ground can be a serious local problem depending on the particular ground conditions.
Pipes and fittings should be protected against corrosion by using an internal lining, an external coating or a corrosion-resistant material. Where contamination of the soil is suspected, or where knowledge of the site raises concerns, an analysis of the soil should be obtained. Extended use of biocides can adversely affect both metal and plastic piping.
Users of this British Standard are advised to consider the desirability of selecting copper tubes for which independent quality assurance certification to BS EN 1057:2006+A1:2010 has been obtained. Generally, copper is resistant to corrosion and is suitable for hot and cold water applications. Where supply waters are capable of dissolving an amount of copper such that unacceptable green staining is produced on pipework and fittings, consideration should be given to the use of water treatment or alternative materials.
In certain specialized installations, such as hospitals in aggressive water areas, the use of copper might not be appropriate due to the risk of contamination resulting from pitting of copper. Copper alloys Copper cannot corrode by dezincification because it does not contain zinc. Other recommended materials are gunmetal, which is also immune to dezincification, and brasses inhibited and treated to be highly resistant to this form of corrosion. For alloys in the latter category, a specific test of dezincification resistance is given in BS EN ISO 6509. For ease of identification, fittings manufactured from grade A dezincification-resistant brasses are marked with the recognized dezincification symbol “CR” or “DRA” .BS 8558 pdf download.