Contractor PBF Drainage has successfully completed a significant repair to a DN375 pipeline at 4 m depth, using the Quick-Lock point repair system, all in just a single shift. The 3-man crew took just 10-hours to install 28 Quick-Lock units in series creating a durable, refurbished section of pipeline which could be instantly re-commissioned. The DN375 diameter pipe included a section of 6 m length where the upper part of the pipe had collapsed. The pipe was inconsistent, with issues with deformation and wall thickness, creating a variation in diameter from 375 mm to 450 mm, plus the following downstream section also looked on the verge of collapse.
The initial assessment of the pipe was undertaken by excavation of the 6 m section, following the first CCTV survey. Further excavation for repair or to examine further pipe sections was impossible due to the precarious condition of the pipe and the challenging site conditions. Certainly, further excavation risked the collapse of the damaged downstream section.
James Stern of PBF consulted with Terry Ingleby of S1E Limited, which distributes the Quick-Lock system in the UK. Their discussions around the requirements of the job and the issues on site concluded that the Quick-Lock system would provide the best solution.
PBF Drainage prepared the site by carrying out low-pressure jetting to clean the damaged pipe. The PBF team installed a patch repair to further shore up the collapsed section, preventing any additional damage whilst the main repair was carried out.
To repair the pipe, a pre-liner was firstly pulled into position. The 28 Quick-Lock units were installed within the pre-liner to keep them in line and to size, ensuring they were expanded to the correct size given the variation in the damaged pipe. This also ensured a good connection into the remaining good part of the pipe, which had already previously been replaced during an earlier repair.
The Quick-Lock units were overlapped during installation, according to best practice for this repair product. The overlap creates a continuous repair and an excellent seal and provides additional strength.
There is no requirement for curing with the Quick-lock system, speeding up the work for the contractor and meaning that the pipeline can be immediately placed back into use following the repair. The contractor has claimed that repairing without excavation and replacement, and being able to do so quickly, has saved their client thousands of pounds. The resulting repair contains sufficient strength to withstand ground pressure and pressure from the backfill used to finish the reparation to the site.
PBF Drainage oversaw all aspects of the job including CCTV survey, cleaning with low-pressure jetting, patch repair and installation of the pre-liner and Quick-locks. The company is in its 10th year of trading and carries out repairs across the UK, using a wide range of professional repair techniques. PBF Drainage is also a member of the UKSTT.
The Quick-Lock System Quick-Lock is an entirely mechanical, seamless assembly system for localised repairs inside pipes ranging from DN 150 to DN 800 (and over 2 m on request) in any common wastewater, well or drinking water pipe system. The system comprises a stainless-steel sleeve and an EPDM rubber seal. The sleeve sits inside the seal and presses and holds it to the inner pipe wall. To install the Quick-Lock, it is placed in position using a packer which is then inflated until the Quick-Lock is tight against the pipe. A patented ratchet system prevents the Quick-Lock from shrinking back. The Quick-Lock system has been successfully used for many years as a repair procedure for closed sewer renovation. It can be installed horizontally or vertically, above or below water level. It is certified by WRc, DIBt, and ASTM and certified by NSF and is suitable for potable water applications. A wide range of sizes is held in stock in the UK by S1E Limited. www.pbfdrainage.co.uk and www.s1e.co.uk
