CPT focuses on the rehabilitation of underground pipe networks through the use of patented Trenchless Technology, ensuring that the world above is not disrupted. Hong Kong’s Chevalier Group began to build the CPT group in 1998 with the establishment of a local construction company, CPR Hong Kong. By 2002, it had built a global group that today leads in developing and delivering clever pipe rehabilitation solutions to construction contractors and urban authorities around the world.

The group is driven by the technical expertise of European based Norditube, an experienced developer of cured in place pipe liner technology, and the Australian based Rib Loc, inventors and manufacturers of the patented and globally awarded spiral wound pipe liner technology.

These technical experts work closely with CPR in Asia and construction experts KMG in Germany and the United Arab Emirates to refine and prove new technologies that are released to CPT’s customer base via a global marketing, sales and technical support network to more than 60 construction and production partners in 44 countries around the world.

Currently, CPT’s construction contractor CPR Hong Kong is executing a project for the Water Services Department of Hong Kong in Water Main Rehabilitation. CPR Hong Kong, with its long background as a pipe rehabilitation contractor, offers a complete range of pipe rehabilitation and services from project management through to CCTV and pipe cleaning to fully rehabilitated pipe.

CPR Hong Kong utilises the products of CPT in Norditube and Rib Loc for the gravity sewer market as well as for the pressurised pipe sector. Over the past few years Norditube has developed a new product for the pressurised pipe rehabilitation market. The new product, NordipipeTM, was especially developed for pressurised potable water pipes.

Over the next 20 years the Hong Kong Government will rehabilitate and replace a total of 8,000 km of water mains and 4,000 km of salt water mains. The mains vary in diameters from 150 to 1200 mm and even go up to 1400 mm for some transportation mains from mainland China. One of the biggest challenges for the Hong Kong market is to improve the water main network underground through state of the art Trenchless Technologies that allow public life above ground to continue as normal.

The specified pipes for this renovation program are mostly 40 years of age or older and several bursts and leaks show that these pipes cannot withstand the required water pressures anymore. These documented bursts and leaks cause water pressures to decrease across the water mains network and with Hong Kong’s building developments getting higher and higher a situation of short supply or lack of pressure to reach the top floors was becoming a considerable risk. In the first half of 2005, CPR Hong Kong has already been awarded projects in the areas of Yau Ma Tei, Tsim Sha Tsui, Mong Kok and Sham Shui Po.

Technical Challenges

The water mains system in Hong Kong is usually operated at a working pressure of 10 bar. Pressure tests post rehabilitation are taken to an extreme level of 50 per cent above the normal working pressure and are conducted at 15 bar to ensure the integrity of the system. Developing a suitable product which would allow CPR Hong Kong to install a Trenchless Technology solution for the specified requirements was a great challenge for CPT. The solution was found with Nordipipe, an integrated glass layer inside a felt-sandwich construction, which made it possible to tackle the challenges as well as the internal and external loadings. Nordipipe is the first self-supporting Cured in Place Process (CIPP) Liner in the market. Its other ingredients, PE coating and a specially developed epoxy resin, make the system suitable for drinking water applications.

Social Challenges

Hong Kong is a very densely populated city and any repair or rehabilitation of pipes requires a quick execution of works. Disruption of traffic is practically impossible during normal daytime hours and most lining operations have to take place in an 8-hour window from 9 pm in the evening to 5 am in the morning. Norditube has therefore developed an epoxy resin that allows the complete curing of the liner in this short time frame, with all eight hours consumed by the setting up of equipment, inversion, curing and remedial works after lining.

CPR’s project management is also mastering other challenges, especially difficulties with bypass pumping during the lining operation. Some of the water mains are operated in loop systems, which do not require any bypass pumping. The bigger diameter main transportation pipes however require by-pass pumping. In Hong Kong’s narrow streets with buildings rising literally from the footpath this is one of the major challenges for the project management.

However, despite the challenges, CPT through its local company CPR Hong Kong and its global technology division Norditube will help to secure the supply of drinking water for the Hong Kong population for years to come.