CS-012 High pressure transmission pipeline of natural gas tee reinforcement

Transmission pipelines are widespread. Most of these pipelines you are not aware of, because they are located underground or at the bottom of the sea. Gas and Oil are typical media transported via transmission pipelines. It is crucial to keep these lines in perfect condition as many times high pressure is involved. This infrastructure also includes block valve stations (BVS) at certain distances. Equipment located in these stations need good maintenance. Inspection discovered welded joints on the gas transmission pipeline did show a high-level degradation. Immediate action was required.

Challenge

The repair challenge in this case was to strengthen the affected weld of a reducing tee (from 18- to 2-inch) at a pressure close to 100 bar. Wrapping a normal tee already is a job that needs to be performed by a trained installer. Wrapping a tee with this large difference in diameter requires even more skills. Together with the client we have designed a flower wrap. This case study will provide you with some inside.

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CS-008 Repairing dents in an underground carbon-steel pipeline

Dents in transmission pipelines are a common problem that need to be fixed as soon as possible. Dents will make the pipeline in that particular area weaker. There is a chance of crack forming or even creation of a hole if the dents are not properly repaired. CTE BV is working with epoxy composites and carbon fiber cloth to save repair the pipeline. Compressive Modular Filler (CMF) is applied to bring back the dent area in it’s normal shape. The carbon fiber cloth in combination with epoxy composites will bring back the integrity of the pipe after curing. The case study explains how to approach a dent defect in your pipeline. The repair is performed according the standard ISO 24817.

Challenge

The repair has to take place under pressure to push out the dent as much as possible before applying the CMF putty and carbon fiber wrap. Often natural gas pipelines are buried and access is only allowed when the installer did receive a confined space training.

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CS-002 Protecting HDD pipeline welding joints with fiberglass wraps

Horizontal Directional Drilling (HDD) is a minimal impact trenchless method of installing underground utilities such as a pipe in a relatively shallow radius along a prescribed underground path using a surface-launched drilling rig. HDD offers significant environmental advantages over traditional cut and cover pipeline installations. The technique is routinely used when conventional trenching or excavating is not practical or when minimal surface disturbance is required.

Challenge

Protecting the welding joints of the 40” diameter pipeline was a challenge because the pipe was pretreated with FBE (Fusion Bonded Epoxy) and not all adhesives would stick to this material.

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CS-001 Repairing an active leak at a natural gas carbon steel pipeline

An active leak in a natural gas transmission pipeline is a nightmare for every gas distributor. It creates an environmental undesirable and dangerous situation that needs to be fixed as soon as possible. Stopping the leak was the first step in the process of repairing the pipeline. In this case the girth welds of the pipe were showing weak points and in one particular case there was a small leak. After the leak was stopped by using a low-profile leak sealing solution provided by CTE BV the engineered carbon fiber epoxy based system was wrapped around the repaired area. The particular area was secured for future leakages.

Challenge

Besides stopping an active leak also the winter circumstances did ask for a professional approach towards a successful repair according ISO 24817.

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