Trenchless Technology

Trenchless technologies are essential to rehabilitation and replacement of existing, and the construction of new public utilities and other underground services without or with little digging of trenches. Utilisation of these technologies provides cost effective alternatives to open cut methods. In addition it reduces the environmental impact and social costs.

There are mainly a few types of trenchless technologies available:

  1. Cured in Place Pipe (CIPP) system

    The basic idea of this technology is to use flexible tube from various materials such as polyester felt with or without glass fibre reinforcement for carrying impregnated thermosetting resin (there are several types of resin for this purpose). The resin impregnated liner is then inserted into the damaged pipe by pressurized water or air. The maintained pressure allows liner to form a pipe.

    Circulation of hot water or steam is needed to cure the resin up to several hours depending upon diameter and section length.

    This technology is suitable for gas, potable and industrial water, sewer, and petrochemical application.

    All gravity and pressure pipe of DN 150mm up to 1600mm can be rehabilitated using this system.



  2. Spiral Wound Liner (SWL) system

    SWL is a spiral wound trenchless pipeline renewal technology design for rehabilitation of existing deteriorated pipe.

    The (Poly Vinyl Chloride-PVC or Polyethylene-PE) profile strip profile is spirally wound by winding machine from the existing manhole into the existing pipe. The edges of the profile joined (mechanical interlocked or welded) while being wound to form a liner. Not limited to circular pipes rehabilitation, odd-shaped conduits like box-culvert or horse-shoe shape are possible with SWL.

    There are various plastic profile/steel configurations to suit the structural design criteria.

    This technology is suitable for gravity pipe of DN 150mm up to 5000mm.

  3. Fold and Form (F&F) system

    Fold and Form liner is another alternative of established CIPP and SWL technology.

    High Density Polyethylene (HDPE) or suitable material is thermo mechanically U-formed in the factory and rolled onto customised spools.

    The liner is pulled from launching point to end point.
    Under controlled curing process (memory effect) the U-liner will expand to its original circular shape and close fit to the damaged host pipe.

    This technology is usually suitable for sewer, gas, potable and industrial water application of DN 100mm up to 400mm.



  4. Pipe jacking system

    The board definition of this technology is to install rigid pipe segments horizontally underground using a shaft where open digging is not possible.

    Most pipes are hydraulically jacked via laser guided tunnelling shield or personnel occupied tunnel boring machine (TBM).

    This technology is suitable for gas, potable and industrial water, sewer pipes application.

  5. Trenchless CCTV Pipe Investigation and cleaning

    Before any rehabilitation works can start a remotely controlled camera to survey and clean the existing pipe.

    The survey is then recorded on VCR or CD including the inspection report for rehabilitation recommendation by a CCTV camera.

    There is existing software that enables us to value/justify the existing pipe condition and document the report systematically. Cleaning process using high pressure water jetter up to 1,500 bars operating pressure depending on the condition requirement.

    There are cleaning equipment is suitable for all kind of pipes from diameter DN 80mm up to DN 2500mm