How to Remove Corrosion in Pipelines

Pipe-lines are essential components in industrial, municipal, and commercial operations, ensuring that fluids and gases can be transported safely. Corrosion due to environmental factors, contact with chemicals, abrasion, improper water treatment, and poor water quality can dramatically decrease pipeline integrity, shorten useful lifespan, and create unnecessary safety hazards. Quick and reliable corrosion removal followed by proactive corrosion prevention will keep your pipelines running strong. This ultimate guide will discuss effective methods of corrosion removal and the equipment necessary to get the job done right for your specific application.

Types of Pipeline Corrosion and Causes

Knowing the type of corrosion you are dealing with and what caused it in the first place can make corrosion removal more effective.

Common Pipeline Corrosion Types Include:

- Electrochemical Corrosion – This rust and pitting happens when your pipeline comes into contact with moisture or electrolytes. This is the most common type of corrosion and is typically seen in underground pipelines and circulating water applications.

- Chemical Corrosion – Corrosion caused by contacting a corrosive fluid. You will usually see this type of corrosion in pipelines found in chemical processing plants and refineries.

- Microbial Induced Corrosion – Corrosion caused by microorganisms, specifically bacteria. These bacteria produce acidic byproducts that then eat away at the metal of your pipes. These pipelines commonly have biofilms and transport water.

- Scale-Induced Corrosion – When scale from minerals buildup on the inside walls of your pipe, it causes corrosion. The scale traps corrosive fluids and electrolytes next to the metal surface promoting localized corrosion.

Ensure you know what type of corrosion and the cause of it before cleaning your pipeline so you can effectively remove the whole corrosion and prevent it from happening again in the future.

Effective Methods to Remove Pipeline Corrosion

Different applications call for different methods of removal. When selecting a method for your operation, consider material composition of your pipe, the severity of the corrosion, the location of the corrosion, and other factors related to stopping pipeline operations. Here are some of our most trusted methods of corrosion removal and the equipment you can use to back them up.

1. Mechanical Removal of Corrosion

Typically used for surface level rust and moderate corrosion. Equipment used for mechanical removal methods rely on some sort of physical force.

Popular Mechanical Methods Include:

- Wire Brushing – Wire brushing by hand is a cheap method for removing loose rust. You can also find machines that wire brush pipelines to ensure even coverage across larger areas.

- Sandblasting – One of the most effective methods of removing corrosion. Sandblasting can make your industrial pipeline meet Sa2.5 surface requirements.

- High Pressure Water Jetting – High-pressure water jets can effectively remove corrosion without introducing chemicals to the equation, making them ideal for sensitive pipes. You can also add an abrasive material to the water to improve its ability to remove rust.

- Rubber Ball Cleaning – Rubber ball cleaning is a very common method of removing corrosion and scale from pipes that transport water, heat exchangers, and condensers. Pipes are filled with balls the same size as the diameter of the pipe. As they bounce around they scrub the inner walls of your pipes free of scale and corrosion. There are no brushes to shred and cause damage like other methods. Since this process doesn’t require you to shut down your pipes, it can be done online.

Consider using an electronic water descaler on your pipelines following mechanical cleaning. One of the leading causes of corrosion is scale buildup on the inside walls of pipes. Electronic water descalers use electromagnetic fields with high-frequency alternating current. This changes the structural composition of mineral ions in the water preventing them from bonding to surfaces. They improve water flow, and are ideal for circulating water systems and cooling towers.

2. Chemical Removal of Corrosion

Methods that dissolve the corrosion are best used for areas that are difficult to reach with other methods and extreme cases of corrosion.

Popular Chemical Methods Include:

- Acid Pickling – Acid pickling uses diluted acids and inhibitors that dissolve the rust without harming the base metal. It is most commonly used for carbon steel.

- Neutralization & Passivation – Complete the pickling process by neutralizing any excess acid. Passivation will also create a thin layer of oxide to protect the metal, this method is ideal for stainless steel.

- Chelation – Chelating agents are environmentally friendly and dissolve corrosion. They are perfect forpipes in hospitals, food production facilities, and anywhere else you may come into contact with humans.

Chemical Cleaning is most effective when using a dosing device. These devices allow for the precise pumping of chemicals, inhibitors, and passivators. Automated dosing pumps can even monitor water quality and regulate chemical dosage in real time. Making your chemical application more efficient and environmentally friendly. These pumps can also be used to help prevent future corrosion buildup while your pipes are in operation.

Prevent Corrosion from Returning with These Posts-Cleaning Tips

Just because you’ve removed the rust from your pipeline doesn’t mean you’re done. In addition to electronic water descalers and dosing pumps, make sure to frequently inspect your pipelines with inspection equipment such as endoscopic cameras and ultrasonic thickness testers. Finding damage early can save you time and money down the road.