Hydro Excavation (NDD) Study: Call for Member's Participation

Tue, 20 Oct 2020

Hydro Excavation (NDD) Study: Call for Member's Participation

AUSJET / ADCVA are planning a project to evaluate the effect of water jetting pressures and flows on different infrastructure assets, when carrying out Hydro Excavation (NDD). Hydro Excavation utilises high pressure water usually in the range of 2000psi to 8000psi at varying flows in conjunction with vacuum, to locate and expose assets in a passive non-destructive method during civil construction projects and maintenance work around underground assets.

There are varying theories about what type of pressure/flow can be used on specific assets, there are some assumptions that a pressure of no more than 2000psi should be used. This was based on a non-published trial completed on a fibre optic cable, the issue with this trial is it’s not only pressure that can damage an asset, but also the technique, water flow and jet size weren’t considered.

If a high-pressure lance sits stationary long enough on an asset, at some point it will cause damage. In addition, the type of nozzle being used can have an effect, for example a pin nozzle is more concentrated in one spot, however, a turbo nozzle that spins can be used to minimise impact on the asset, whilst still being productive.

Hydro Excavation is used extensively throughout the world; Australia, North America, Europe, UK, Asia and Canada and to our knowledge no organisation has ever completed a comprehensive study on pressure/flow/ nozzle size/techniques to be used regarding different asset material types.

  • Pressure – what pressures are causing damage to different underground services
  • Water flow – what is the optimum water flow for each asset
  • Nozzle Size – How does that play a part in optimizing productivity but not damaging the asset
  • Single jet V’s Rotating nozzle – what is the time differences with regards to damage of the asset
  • Technique – are their differing techniques to best protect the asset and reach improve production
  • What innovative automation technology can be introduced to take the operator away from the lance

AUSJET / ADVCA proposes to carry out studies on the following assets:

  1. Fibre Optic Cable
  2. Underground Power Cable
  3. High Voltage & Low Voltage electrical cable
  4. Potable Water Pipes
  5. Storm Water Mains
  6. Sewer Mains

AUSJET / ADVCA have partnered with a number of contracting companies that can provide samples of each asset to run the tests, also AUSJET / ADVCA along with its members can facilitate operational displays, live job site studies for the researcher to determine how the work is performed in the field and what the challenges are, technical information around pump sizes and water flow. AUSJET / ADVCA’s plan is to complete the study and present the findings at AUSJET21.

AUSJET / ADVCA are calling on our members and other relevant industry associations and industry bodies to provide input, participate in the study and endorse the study. As a member of AUSJET / ADCVA should you wish to participate or have any comment on the scope and other inclusions, please contact support@ausjetinc.com.au.

Lance McKay, the board member heading up this project will then be in touch to follow up to discuss any proposed participation or feedback.

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