Applus+ has successfully completed the installation of the largest diameter CIPP GRP liner in Qatar

Recently, Applus+ Velosi in Qatar’s CIPP lining team installed a 59m 800mm diameter CIPP GRP liner at a project site in Doha. This is the first time ever that a UV GRP liner of this size (DN800) has been installed in Qatar.

No-Dig or Trenchless Technology is the discipline of installing, repairing or renewing underground pipes, ducts, and cables using techniques that minimise or eliminate the need for excavation.

Cured-in-place pipe (CIPP) is one of several trenchless rehabilitation methods used by Applus+ Velosi to repair existing pipelines. CIPP is a jointless, seamless, pipe-within-a-pipe with the capability to rehabilitate pipes ranging in diameter from DN 100 to DN 1600. The process is carried out through the manholes, avoiding excavation and traffic congestion.

There are several different materials and methods of curing. Applus+ Velosi uses reinforced glass liners which are cured using UV technology. The majority of pipes being rehabilitated using CIPP are sewer and drainage; these lines will have internal failings and infiltration problems. Once lined these pipes will be secure for up to 50 years.

During the installation, there were many challenges, the main one being the amount of infiltration coming from a 45m longitudinal fracture at the inversion of the pipe. Applus+ Velosi and their client came up with an innovative solution to dewater next to the pipeline and lower the water table; this enabled us to install the liner in dry working conditions.

The client was extremely satisfied with the result.