Towards a knowledge programme for PVC pipe systems

PVC is the most used pipe material

PVC has been used in the Dutch drinking water distribution network since around 1955. Today, more than half of the network (over 60,000 km) consists of pipes, joints and fittings made of PVC. A thorough description of the historical development of the drinking water distribution network that focuses on the introduction of PVC has for instance been written by Mesman en van Laarhoven (2018). Among the advantages of PVC are its strength, inexpensiveness, chemical stability and – which later became clear – its high recyclability. PVC is, for the moment, one of the least failure-prone pipe materials in our distribution network. PVC failures do however constitute a significant portion of the annual total, because such a large proportion of the network is made of PVC.  Failures in PVC pipes of large diameter can cause a great deal of nuisance and involve high costs because big cracks can occur in these large pipes. It therefore remains important to understand and control failures in PVC pipes.

Contact group, failure database analysis, informed choice for knowledge programme

This project’s activities are focused on:

• A contact group of partners that can play a role in the knowledge programme.
• An analysis of the historical failure database, with a focus on the general core data about PVC pipe systems; on the question as to whether utilities will benefit from a technical-substantive added value gained from sharing their failure data (or whether the volume of their own data is now statistically of sufficient volume); and on the identification of different groups (cohorts) of PVC pipes, for which specific knowledge will need to be built up in the knowledge programme (presumably with the use of a series of techniques, each always applied to pipes selected from the each of these cohorts).
• A consolidated overview of data on the material properties of PVC pipes, collected from different relevant organisations, resulting in:
  • insight into the effort involved in working together in this kind of data field;
  • insight into the expressive power of the kind of data that have been collected to-date concerning distribution network management, with a view to having a benchmark for a knowledge programme.
• An interpretation of the implications of recent fundamental research (in any event, of two recent doctoral theses on this subject) for the drinking water utilities and/or the knowledge programme.
• A widely supported decision on whether or not to establish the knowledge programme, and, if so, which method development to draw upon (D to J in Figure 1).

Figure 1. The knowledge programme for PVC pipe systems involves various building blocks. In this phase, we are focusing jointly with the drinking water utilities on how we can give shape to such a programme.

Provide drinking water utilities insight into the effort required

The outcomes of this project will support drinking water utilities with knowledge about the efforts required in the years ahead, with a view to further improving the management of existing and yet-to-be-installed PVC pipe systems.