Industrial pipeline cleaning is a vital maintenance procedure in the petrochemical industry, directly impacting operational safety, product quality, and equipment lifespan. Depending on the type of deposit, pipeline structure, and site conditions, the following methods are commonly adopted:

Method 1: Mechanical Cleaning

Mechanical cleaning involves using physical tools to scrape contaminants from the internal pipe surface. It is most effective for long, straight sections of pipeline with minimal bends or branches. Common tools include:

• Scrapers – Ideal for removing thick, solid deposits like wax or coke.

• Steel Brushes – Effective against rust layers and hardened scale.

• Pipeline Pigs – Inserted into the pipeline and pushed by fluid or gas pressure, these devices clean by scraping and displacing debris.

While mechanical cleaning is relatively simple and cost-effective, it may struggle to clean complex pipeline geometries, leading to blind spots. Additionally, it is less efficient for removing oil-based or chemical residues.

Method 2: Chemical Cleaning

Chemical cleaning uses various agents—acids, alkalis, or solvents—to dissolve or break down contaminants on a chemical level. It is particularly suitable for complex systems with varied deposits:

• Acid Cleaning – Removes rust, carbonate scaling, and oxide layers.

• Alkaline Cleaning – Targets organic matter like grease and carbon deposits.

• Solvent Cleaning – Dissolves viscous oil residues and organic films.

This method delivers deep and uniform cleaning even in branched or intricate piping. However, strict control of chemical concentration, temperature, and reaction time is necessary to avoid equipment corrosion or the release of hazardous gases. Adequate ventilation and personal protective equipment (PPE) are essential.

Method 3: High-Pressure Water Jet Cleaning

High-pressure water jetting is a chemical-free, environmentally friendly technique that utilizes powerful water streams to remove tough deposits. Key characteristics include:

• Operating Pressure: Water is pressurized to 50–200 MPa using specialized pumps.

• Effective Removal: Efficiently strips away rust, scale, grease, and coke buildup.

• Versatile Application: Suitable for cleaning straight pipes, heat exchangers, towers, and tanks.

Though highly effective, this method requires careful pressure control to prevent damage to pipe walls.

Method 4: Nitrogen Purging and Drying

Nitrogen purging involves displacing air or hazardous gases from pipelines and equipment using inert nitrogen gas. It is often used before and after other cleaning processes to improve safety and effectiveness:

• Before Cleaning: Flushes out flammable, explosive, or toxic gases to establish a safe environment for chemical or high-pressure cleaning.

• After Cleaning: Rapidly removes residual moisture or cleaning agents to minimize corrosion or contamination.

For high-pressure applications, a nitrogen booster is typically employed. It compresses low-pressure nitrogen to the desired level, ensuring thorough gas displacement and efficient drying.

Integrated Cleaning Strategy

Pipeline cleaning in the petrochemical sector often requires a tailored combination of methods based on the specific pipeline layout, type of contamination, and transported fluid. Among these, nitrogen purging and drying, enhanced by a nitrogen booster unit, plays a critical supporting role—improving the safety, efficiency, and reliability of the entire cleaning process.