TPi January 2016

Pipe rehabi l i tat ion & repai r

Freeze sealing for pipe repairs Contractors and maintenance personnel involved in repairing pipework in buildings and other constructions have long faced the problem of making repairs on tubes and pipes when they are full of fluid and may not be economically viable to drain. without draining or shutting off the entire system. The controlled ice plug only forms beneath the Accu-Freeze jacket. It does not expand outside of this area and does not create enough pressure to affect the integrity of the pipe.

kept below certain limits. The Accu- Freeze technique is able to freeze large diameters and control the entire freeze process. Huntingdon Fusion Techniques – UK pipefreezing@huntingdonfusion.com www.huntingdonfusion.com

The Accu-Freeze ® pipe freezing system is able to freeze a plug in fluid either side of a repair zone, isolating it, to allow work to be carried out without draining the whole system. Luke Keane, technical support at Huntingdon Fusion Techniques (HFT), said, “Accu-Freeze utilises liquid nitrogen (LN 2 ) in a controlled way to freeze stationary liquids in a selected section of pipe or tube. “By controlling the surface temperature of the pipe or tube, Accu-Freeze can accurately and safely form an in-line ice plug, capable of withstanding 136 bar in diameters up to 12" (300mm).” To form an ice plug, the water or liquid inside the pipe or tube is brought to a static condition and a specially designed insulated jacket is placed around the section to be frozen, upstream from the repair zone. Once the plug is formed, maintenance and repair can take place

Accu-Freeze uses liquid nitrogen to freeze stationary liquids, to form an ice plug inside the tube

The primary advan- tages of the patented Accu-Freeze system include the increased freezing capability of LN 2 and the ability to control the pipe wall temperature throughout the freeze process. injections are automated, which reduces the operator’s workload and reduces the amount of LN 2 that is consumed. can also be operated remotely, which makes it suitable for use inside ‘hot’ nuclear areas where personal exposure must be The LN 2 Accu-Freeze

Clamps vs composites Composite repair specialist IMG Composites has published a new white paper on the subject of composite pipe repairs versus the more traditional repair technique of utilising clamps.

whose background is in mechanical engineering, and who previously worked on designs for steel fabrication before joining the technical team behind the award-winning CompoSol ® repair technology in 2013. The white paper looks at the definition of the two different repair types before exploring the selection process, operation aspects, technical aspects and commercial aspects, and then drawing conclusions. This is followed by an examination of case studies for both the traditional and new techniques. MG Composites commercial manager Ian Taylor stated, “The article is an excellent addition to our technical database, which serves as an invaluable information resource for our personnel.

We chose to publish this in order for our clients and partners to better understand the issue. “It is not a matter of pretending com- posite pipe repairs are a panacea for all problems; instead the article is designed to help clarify areas where composite pipe repairs are more advantageous than clamps and vice versa.” The subject of clamps vs composites is also briefly explored at www. compositepiperepairs.com, an IMG Composites website dedicated to composite pipe repairs.

The paper, which was published on a free-to-view online platform accessed via the IMG Composites website, provides detail on the benefits and disadvantages of using each method. The technical department at IMG Composites works on studies of many aspects of the composite repair business, often writing technical service reports for the information of clients and internal development. The paper is primarily the work of technical support engineer Stuart McKay,

IMG Composites Ltd – UK contact@imgcomposites.com www.imgcomposites.com

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January 2016 Tube Products International