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Valves are essential in drinking water distribution networks to ensure continuity of supply. OptiValves leads to an optimal valve maintenance programme over the life-cycle of a drinking water distribution network, including an improved inspection procedure per valve and a maintenance programme targeted at the most important valves in the network.

OptiValves benefits:

  • Insight into how a targeted valve maintenance programme will enhance network performance and reduce maintenance costs.
  • Better understanding of how valves affect the performance of drinking water distribution systems.
  • Improved performance of the most important valves. Management support on the operational and tactical level.

Read a news item on what can go wrong when valves fail >>


OptiValves consists of a comprehensive manual on how to evaluate and improve the valve inspection and maintenance procedure (inspection protocol), plus the CAVLAR software.

The manual takes into account the most important local failure mechanisms and helps to determine the best inspection interval. CAVLAR, in turn, enables one to determine which valves to inspect more frequently. Altogether, this will enhance the network’s performance and reduce maintenance costs. It is also possible to consider local pipe failure rates per pipe material and vulnerable customers, such as hospitals.

Download the CAVLAR-manual


Using the CAVLAR software can lead to more efficient and more effective valve maintenance, thus reducing costs.

CAVLAR’s implementation steps:

1. Efficient valve maintenance (inspection protocol):

  • Information collection:
    in a pilot, checks valves using good inspection forms and good recording of findings.
  • Information processing:
    you perform a statistical analysis of valve failure mechanisms.
  • Results presentation:
    you calculate the failure probability of valves (input for step 2, Effective valve maintenance).
  • Context:
    your client adjusts the inspection protocol and targets maintenance at the most important failure mechanisms.

2. Effective valve maintenance:

  • Information collection:
    1) use or construct an EPANET model of the distribution network (.inp file) including the valves.
    2) import the file into CAVLAR and enter the failure probability of pipes and valves (this results from the valve inspection in step 1, Efficient valve maintenance).
  • Information processing:
    CAVLAR calculates the performance of the distribution network for different scenarios (different network configurations or different failure probabilities).
  • Results presentation:
    you can copy and paste CAVLAR’s results into an .xls file. You then import this file into the accompanying presentation tool, which transforms the different scenarios into side-by-side charts. This allows you to visually compare the scenarios.
  • Context:
    you analyse the results and advise your client on which valves should be given maintenance priority.

Download test models

It is possible to use different types of network diagrams of the considered distribution network as input for CAVLAR. For each type of model a test model is available. These test models can be used to try CAVLAR or to check the desired information in the format of the different models.

In imported Aleidmodel, Epanetmodel en Excelfile format II, the following information need to be filled, before calculation with CAVLAR is possible:

  • feeding sections (‘V’): for this network A_25Y and K02590
  • failure probability: free to choose (default 0.05)
  • valve reliability: free to choose (default 0.95)

Use hyperlinks below to download the desired test model:

Models to import:
Epanet project
Excelfile format I
Excelfile format II
Infoworks-based-CSVfile project:
Aleid project

Models to open:


There are several forms of support available to ensure that you optimize your use of OptiValves, and that you are updated on all the latest developments. Specifically, you can make use of the following options to suit your particular situation:

  • A short introductory – or more elaborate – course on OptiValves for you and your clients.
  • Expanded or modified OptiValves functionalities to create tailored solutions.
  • Consultancy services, including technical and organizational process management, raising support for change and reporting.
  • Access to OptiValves-related projects or research.


Mentioned in: 4 Publications
Enrolled in: 4 Cases in 2 Countries

  • Blokker, M., Pieterse-Quirijns, I., Postmus, E., Meira Marmelo, V., and Laurenço, L.
    Asset management of valves
    Water Asset Management International, 7(4) (2011), 12-15.
  • Trietsch, E.A. and Vreeburg, J.H.G.
    Reliability of valves and section isolation
    Water Science & Technology: Water Supply, 05 (02 2005), 47-51
  • Van Thienen, P., Vloerbergh, I., and Wielinga, M.
    “Characterization and Effects of Valve Management at Dutch Water Companies”
    LESAM 2011, Mülheim.
  • Vreeburg, J.H.G., BLokker, E.J.M., Rietveld, J., Sluijs, A.A.I., and Botterblom, S.
    “Hydrant maintenance as example of targeted asset management”
    LESAM 2011, Mülheim.

Tool Expert(s)

Mirjam Blokker

Principal scientist, KWR

+31 (0) 30 60 69 533

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