When this is done over a period of time it can be the case that even newly laid drainage pipes can become laden with set concrete which then has to be removed to ensure the long-term viability of the drainage system. This was the case recently on a major construction undertaking for a significant residential construction project in the burgeoning Docklands area in London’s East End.
After searching the market for potential options to clean the affected pipes, and trialling cleaning from various other cleaning contractors, the contract to complete the concrete removal process was awarded to specialist pipe cleaning company Tube Tech International Ltd of Rayleigh, Essex, U.K.
Tube Tech specialises in fouling removal across virtually all industries. The company is often called on to implement its specialist fouling removal after other more traditional jetting and cleaning contractors have tried and failed to remove the blockage. Clients are usually at the point where the fouling problem is seemingly impossible to overcome and so they are considering pipe replacement as the only option. According to Mike Watson, Managing Director of Tube Tech: “It is at this point where we can offer a better alternative.”
After decades of operation in the field Tube Tech has developed a range of simple yet effective remote control systems and robotics specifically for fouling removal purposes. In many cases equipment suited the case in hand may be developed.
CLEARING CONCRETE FROM PIPES
The requirement to re-establish the correct flow regime in the concrete laden pipes serving the new buildings on a recent site proved to be quite urgent, so initially Tube Tech was asked to rapidly mobilise with what might be the best equipment available to them at the time.
Having been involved for some 30 years in specialist fouling removal operations from all types of process assets in all industries, including utilities as well as oil and gas, Tube Tech International has become recognised as a global leader in research-led, high tech cleaning and inspection services. The company has continually developed tried and tested, step change methods to solve heavy industries most difficult fouling removal challenges across the world providing simultaneous re-opening and inspection services for a wide variety of industrial situations enabling significant savings to be made by clients by reducing downtime, cutting CO2 emissions, increasing throughput and improving safety standards.
Previous experience in the removal of concrete from pipework enabled Tube Tech to bring to the site one of its proven systems. This option had some effect for removing the concrete in the pipes at up to four times more than any previous contractor. However this still proved too time-consuming an option for the client. What made the works somewhat more demanding was that there were no drawings of the pipe network available so until the Tube Tech team arrived on site any cleaning work was effectively done blind.
After the initial attempts to remove the concrete proved too slow, Tube Tech’s expertise was brought to bear given the experience and better understanding of the problem. The team regrouped and ultimately was able to develop better technology that could cope with the limited access to the affected pipeline within the confines of the construction site as well as handling the tight bends that proved to be within the pipe network as well as being a faster concrete clearing method. Part of this solution was the development and introduction of the use of polymer infused ultra-high pressure water, to create more impact against concrete blockages in order to remove it quicker.
As part of this process, Tube Tech found a biodegradable chemical which could be used to soften the set concrete in advance of any cleaning operation. This alongside the use of various mechanical tooling and high pressure jetting meant that ultimately to achieve full removal of the concrete obstruction in the drainage pipe required the use of some four different technologies.
The success of the fouling removal operation, once the effective new methodology had been developed and applied, was eventually complete in just 5 working days.
LIMITING PIPE DEGRADATION
One of the more important aspects of the site work, as well as completing clearing of the concrete obstruction, was limiting any potential damage to the pipeline material.
As with any situation where the obstructing material is harder than the material from which the pipe is made, there is always the potential for damage to be incurred by the pipe fabric. This was the case on the recent project. When interchanging the various mechanical and jetting heads to remove the concrete from the pipe occasionally Tube Tech’s equipment became stuck in the pipe after passing over the obstruction into clear pipe or as sections of concrete broke away from the main body of the obstruction. This meant that operations to remove the devices or jetting heads and even some of the ultra-high pressure water operations caused some minor damage to the inner surface of the pipe.
As the concrete removal operation ended Tube Tech undertook a full pipeline inspection to highlight where any damage had occurred during the works. In the end only about 5% of the pipeline showed any damage, far less than might be expected of such a difficult cleaning operation.
The extent of the damage that did occur within the pipe was considered minor leading the client to accept the outcome of the works completed and was subsequently more than happy to have the concrete cleared. Any sections that were damaged could be re-sleeved and remain in service into the future. However, due to time constraints on other affected parts of the construction project, some sections of pipe that were blocked by concrete were required to be bypassed by the installation of new pipe lengths
Commenting on the concrete clearing operation Mike Watson said: “We have been concrete clearing on projects of this nature for many years although it is not usually the main thrust of our operations. But this one threw several challenges at us that even we had not met before. Working together and pooling the experience of our crew and technical team we were able to come up with a methodology that ultimately enabled us to complete the job to the full satisfaction of the client. On site it was the skill and tenacity of our crew that made this operation successful with very little damage to the pipes in question. The whole team should be very proud of the work it completed.”
Tube Tech International Ltd
14 Rawreth Industrial Estate
Essex SS6 9RL
Tel: +44 (0)1268 786999
Fax: +44 (0)1268 786998