Mechanical cleaning vs. chemical cleaning

Mechanical cleaning of pipelines is still one of the most commonly used methods among pipeline owners, because it’s cheaper and does not require specific technical expertise. However, dry pigging only displaces the debris from the 6 o’clock position to 360° around the pipe wall, coating the pipeline wall with a thin layer of deposit. Additional mechanical pigging will compact this layer, which can lead to a number of problems, such as under deposit corrosion, nuisances downstream and less accurate readings from an inspection tool.

Advanced chemical cleaning

Chemical cleaning, by definition, means the use of liquid cleaners mixed in a diluent (water, diesel, methanol, iso-propyl-alcohol and alike) to form a cleaning solution that can be pushed through a pipeline by pigs. Advanced chemical cleaning in conjunction with specially engineered pigs removes a greater volume of debris in fewer runs.

The advantages:

• Cost reduction;
• More reliable integrity checks;
• Increased operating capacity;
• Improved condition of your pipeline network.

There are various manufacturers of cleaners. However, a careful choice of pipeline cleaners should be based upon the following characteristics:

• A neutral pH;
• Deposit permeating and penetrating capabilities ;
• Original design parameters of the cleaner;
• Health & Safety awareness; and
• Case histories.

Pipeline cleaners that dissolve solids could form harmful gases and be detrimental to pipe-wall metals. Most gel types are carriers only and rely on mechanical pigs to disassociate solids from the pipe walls.

N-SPEC® advanced chemical cleaning agents provide a more effective and environmentally friendly solution than most current chemical cleaners. N-SPEC® products have no effect on any metallurgy. Caustic flushing is not required thanks to its neutral pH.