ISO/TC 5/SC 2/WG 24 - Internal Protection

This document provides details about the aggressiveness factors, evaluation indicators of raw water, or inlet water of ductile iron pipe system and relevant lining information applicable to ductile iron pipes, fittings and accessories used in water mains and distribution system. This document is intended to serve as a tool for estimating the properties of certain water and their effect on internal linings of ductile iron pipes, fittings and accessories used in water mains and distribution system which are specified in ISO 2531, ISO 16631 and can be used to decide the most appropriate protective measures to ensure long term durability of pipeline. It is not always possible to definitively determine the aggressive parameters of certain water, and fully considered by limited test and evaluation. Therefore, the history information of the evaluated water, experiences of local water works can be taken for reference. The aggressiveness evaluation of water can be carried out before determining the internal lining materials of certain pipeline, and the evaluation and relevant tests can be done by qualified laboratories and engineers. Water that leads to high-level scaling in the pipeline is believed aggressive. Drainage and waste water are not in the scope of this document, the internal protection of drainage and waste water can be recommended by pipe suppliers.

ISO 4179:2005 specifies the nature, the method of application, the surface condition and the minimum thickness of internal linings of cement mortar for ductile iron pipes and fittings for pressure and non-pressure pipelines as defined in ISO 2531 and ISO 7186. ISO 4179:2005 covers cement mortar linings which are used to improve the hydraulic properties of pipes and fittings compared to un-lined pipes and fittings and/or to prevent corrosion damage and includes special requirements for linings of gravity sewers operating partially filled. ISO 4179:2005 also covers linings used for the conveyance of particularly aggressive fluids, where the following solutions may be used either separately or in combination: a) an increase in the thickness of the lining; b) a change of the type of cement; c) a coating over the lining.