Sewerage & Drainage Inspections

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Sewerage & Drainage Inspections

ROBOTIC LASER PROFILING & CCTV INSPECTION SERVICES

As one of the fastest growing economies, development of modern public infrastructure including underground water and sewerage supply network is on rapid growth in India. Since most of this network is laid underground, any future maintenance activity that comes up due to some workmanship defects is very expensive. Such unnecessary expenditure can be avoided by proper/intrusive inspection of such assets before commissioning. Since most such assets are non-man entry pipes, manual intrusive inspection is not possible and hence robotic conditional assessment survey becomes a necessity. Further, maintenance activities involving sewer works often involve manual intervention causing unnecessary risk to human lives. Using robots to perform such tasks can save such risks o human lives and put an end to manual scavenging once and for all.

 

Robotic Inspection methodologies eliminates the risk to human life. The data generated using such inspections can be integrated with existing GIS data of the ULB which helps in future asset management. The generated inspection reports can be used as a reference to plan any future regular maintenance activities. Such inspections can also be done in running sewer pipelines to ascertain their current condition and identify & locate faults if any. Old & running pipelines can be graded on a scale of 1-5 (as per internationally accepted WRc norms) which helps in establishing the pipe’s RUL (Remaining Useful Life).

Advantages of Robotics Sewer Pipeline Inspections

  • Robotic Inspection methodologies eliminates the risk to human life
  • The data generated using such inspections can be integrated with existing GIS data of the ULB which helps in future asset management.
  • The generated inspection reports can be used as a reference to plan any future regular maintenance activities.
  • Such inspections can also be done in running sewer pipelines to ascertain their current condition and identify & locate faults if any.
  • Old & running pipelines can be graded on a scale of 1-5 (as per internationally accepted WRc norms) which helps in establishing the pipe’s RUL (Remaining Useful Life).
      

Advantages of Robotics Sewerage Inspections for the Contractor

  • Since current condition of the pipeline is not known, hence Sewerage Contractors build in a lot of buffers to account for the unforeseen defects in the pipeline or run a high risk of losses. A 100% inspection would allow the bidders to evaluate the pipeline data before submitting a proper quotation and save exchequers money.
  • Introduction of the 3rd party inspection policy, will provide a chance for the small contractors to start bidding in projects that would have earlier required purchase of inspection system. This provides a level playing field to small contractors in government tenders.
      

Applications

  • Evaluation of work quality of entire underground sewerage maintenance jobs like pipeline desilting and rehabilitation works. This further bifurcates into some distinct application verticals like:
    • Post-Desilting CCTV Inspection
    • Post-Lining CCTV Inspection / Post-Rehabilitation CCTV Inspection
  • Inspection of newly laid pipeline assets, especially, underground sewerage networks.
  • Conditional Assessment and RUL evaluation of current sewerage pipeline assets. DSI’s unique inspection capability allows for online inspection of sewerage pipes which can be executed without any flow intervention.
  • Detection and localization of faults within sewerage network like ground water ex-filtration and in-filtration whenever it is suspected.
      

ONLINE SEWER INSPECTIONS & SONAR PROFILING

Consultants preparing for DPR often need to assess the condition of city’s sewerage network so that they can arrive at a more cost-effective technically justifiable proposal that helps the concerned municipal body save precious taxpayer’s money. However, the underground nature of these assets often limits these consultants to simply guess the entire condition of the network based on manhole surveys and collected CSO data (Critical Sewer Overflows). But not anymore.

 

Starting in 2014, DSI introduced its unique Online Sewer Inspections Technology using which we were able to perform live inspections of running sewers. What’s more was, we used two sets of sensors, visual as well as acoustic, to completely profile of the running sewer and better assess its conditions. Several successful projects have been completed till date and these inspections have the respective municipal corporations save several crores of taxpayers’ money.

 

DSI uses a special sonar device which has been specially customized for operation inside sewer to assess the condition of the pipe under the current waterline. While the visual CCTV camera assesses the pipe’s condition above the waterline, a sonar helps in assessing the silt level and pipes structural integrity under the waterline, thus generating a complete picture of the sewer pipe.

Advantages of Online Sewer Inspections

  • No Intervention Required
  • No de-Watering Required
  • No Flow-Diversions
  • No Interruption of Service
  • Acoustic Profiling of Pipe
  • Silt level/Volume Estimation
  • Pipe Location & Underground Pipe Tracing
  • GIS Mapping
  • Pipe Gradation Report
  • Conditional Assessment & Pipe Defect Code Identification as per WRc Standards
      

LASER PROFILING

DSI developed its own Laser Profiling technology in 2017. Since then, DSI has been actively providing Laser profiling services to Sewerage Rehabilitation contractors to help eliminate the old error prone & labor intensive mandrel method. Laser Profiling is used by rehabilitation contractors to accurately measure the pipe shape and diameter using a laser projected inside the pipe. The obtained data is then used by the contractor to design the liner used for pipe rehabilitation.

Old Method (Mandrel Passing)

  1. Contractor desilts the pipe thoroughly.
  2. Once the pipe is clean, contractor takes diameter measurements along pipe length. The measurements are made by hand using a standard tape.
  3. These measurements are then used by an experienced engineer to arrive at a mean pipe profile size.
  4. A mandrel is fabricated out of Mild steel.
  5. Labor further enter the sewer pipe along with the fabricated mandrel. A designated experienced engineer also enters the pipe.
  6. Mandrel is pushed through along the pipe length. If the mandrel passes through the pipe smoothly, it is designated as the final size.
  7. If the mandrel does not pass through the pipe smoothly, the engineer makes some adjustments to its sizing and fabrication is repeated.
  8. The entire process is repeated until the mandrel passes through the pipe smoothly.
  9. The final accepted mandrel size is recorded and the contractor orders the liner of the same size which is then used for rehabilitation of the sewer pipe.
      

New Method (LASER Profiling)

  1. Contractor desilts the pipe thoroughly.
  2. Once the pipe is clean, a laser profiling survey of the pipe is executed by DSI.
  3. The data gathered by the laser profiler is used to calculate the maximum size of liner that can be used to rehabilitate the said pipe.
  4. The contractor takes these values and order the liner which can then be used to rehabilitate the sewer pipe.
      

As is evident, laser profiling leads to considerable time savings which directly translate to financial gains for the contractor (reduced amount of time required for flow bypassing, etc) and municipal body.

 

Besides sewer pre-lining profiling, laser profiling services can also be used for:

  • Post Lining Pipe Profiling to assess the ACTUAL installed pipe diameter and OVALITY.
  • Quantitative assessment of Pipe Corrosion & Loss in Pipe Wall Thickness.
  • Profiling of Cannon Bores & Torpedo Shafts for ships, submarines and tanks.