Utility Location, Leak Detection, GPR & Concrete Scanning, Pipeline Relining & Rehabilitation, CCTV & LiDAR Pipeline Inspection Specialists

Orsco

Trenchless Rehabilitation Technologies CIPP & ASOE Technical Case Study

DN500MM ASBESTOS CEMENT TRENCHLESS REHABILITATION

INCLUDING 8 X BENDS, TOTAL  173 METERS

The client, Sun City Resort in the Bojanala Region of North West province of SA, used the Lock Down (announced by our {president Cyril Ramaphosa to begin on March 26th 2020,) as the perfect time to conduct routine maintenance to the hotels, casino and water parks. One such project that was tackled was the main water supply pipeline at the Valley of the Waves due to the high level of water loss (1000’s of litres weekly) that was taking place.

After an investigation using CCTV Inspection, Pipeline Location, pressure testing and other condition assessments systems, Orsco (Pty) Ltd identified many misplaced joints, broken and jammed butterfly values, numerous pinhole leaks and not  pipe material degradation due to age (the pipe being more than 28 years old,). The entire pipeline was found to be in very poor overall condition.

After survey results were analysed by our surveying technicians & lining rehabilitation engineer Mr Alaster Goyns recommendations were made and forwarded to Mr Bret Hoppe & Mr Thulani Malinga of Sun City  that rehabilitation of the DN500 was necessary.

After survey results were analysed by our surveying technicians & lining rehabilitation engineer Mr Alaster Goyns recommendations were made and forwarded to Mr Bret Hoppe & Mr Thulani Malinga of Sun City  that rehabilitation of the DN500 was necessary.

The 500mm diameter supply pipeline runs from the pump room around the edge of the valley of the waves, a total length of 173 meters. Excavating to replace and install a new pipeline would have meant weeks and possibly months of no water supply and the added expenses of the new pipeline, excavation, installation etc.

Orsco (Pty) Ltd offered the alternative solutions of the ASOE in-line and Nu Cure Lining technology to the Client, highlighting the fast turnaround time without the need to excavate at crucial access points and how the disruption to the park features would be minimized. Orsco offered the fastest, safest and most environmentally friendly solution available which was a combination of a short length of CIPP and the balance being the ASOE hose. Although this was the first time the latter was to be used in South Africa and the Client  accepted in view of the technical and economic the advantages provided.

Rehabilitation Method

The first 36 m section was rehabilitated by Orsco and Nu Cure Laboratories using a triple layered 100% glass epoxy liner – this was because no other technology was viable at the time to accommodate the sharp double 90-degree bends. This was compounded by four different pipe materials in the section before and after the double 90 degree bends namely:

  • Rubber coating
  • Old existing CIPP Epoxy
  • Steel pipe
  • Asbestos Cement

These sections needed to be cleaned and the substrates prepared .

It was decided that the 137 m of pipeline between Pit 1 and 2 would be re-lined with a pull in place  ‘lay-flat’ type Asoe liner which is used for pressurised pipelines.  Three options were submitted, and the decision-making process was carried out between the Contractor & Client and the proposed solution with terms and requirements for each was agreed upon before implementation.

The Challenge:

A working combination of CIPP and ASOE through carbon steel, cast iron, rubber lining, previous CIPP, Asbestos cement through two double 90’s and then another 6 bends.

 SUMMARY

Transported: Water

Host Pipe Diameter: DN500

Host Pipe Material: Carbon Steel, Cast Iron, Polyethylene and Asbestos Cement.

Total Length:  CIPP – 36m, ASOE – 137m = Total 173meters                                                                                                                               

Operating Pressure: 1 bar, test pressure: 1,5 bar

Systems Used: Nu Cure G2 DN 500 liner, polymer epoxy & ASOE PE/PE covered press-flat Pipe-in liner DN 500

Breakdown: The project was broken up into 3 phases, condition assessment, CIPP and Pipe-in Liner.

 

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