Internal and External Surface Sandblasting and Rust Removal for Steel Pipes

Global Advances in Internal and External Surface Sandblasting and Rust Removal for Steel Pipes

A wide range of sandblasting and rust removal techniques is used for steel pipes worldwide. The primary methods include:

Rust Removal Techniques in China

Manual Rust Removal：

• Using tools such as wire brushes, wire cloth, or coarse sandpaper to wipe the steel pipe surface and remove rust layers.

• Suitable for scattered or small-scale tasks as well as outdoor construction.

Mechanical Rust Removal：

• Using rotary or impact rust removal tools, such as external pipe descaling machines or flexible shaft internal descaling machines, to clean rust from the steel pipe surface.

• Suitable for large-scale and concentrated pipe rust removal.

Sandblasting Rust Removal：

• Using compressed air through a spray gun to generate a strong impact force, blasting sand particles (or other abrasives) onto the steel pipe surface. The impact of the abrasive against the metal surface achieves rust removal.

• Sandblasting offers advantages such as simple operation, high efficiency, and excellent rust removal. However, it produces significant dust during operation, so protective measures are required.

Pickling Rust Removal

• Using chemical agents (such as phosphoric acid or hydrochloric acid) to pickle the steel pipe and remove the rust layer.

• Before pickling, grease and oil on the pipe wall must be removed; after pickling, loose residues on the pipe surface should be thoroughly cleaned.

  
  

High-Pressure Water Rust Removal

• Using high-pressure water jets to flush the steel pipe surface, quickly removing rust layers and attached contaminants.

• Suitable for large-scale and concentrated pipe rust removal. However, it may not be sufficient for severe rusting and often needs to be combined with other rust removal methods.

Rust Removal Methods Abroad

Rust removal methods for steel pipes overseas are generally based on the same principles as those used in China, but often place greater emphasis on environmental protection, efficiency, and automation. Below are some notable rust removal methods used internationally:

Electrolytic Rust Removal:

• Utilising the chemical reaction between the electric current, the steel pipe, and the electrolyte to transfer rust from the pipe surface into the electrolyte.

• Electrolytic rust removal is environmentally friendly and causes relatively little damage to the steel pipe, but it requires more advanced equipment.

Vacuum Sandblasting Rust Removal:

• Using a vacuum system to immediately collect the abrasive particles after blasting makes it suitable for localised rust removal.

• This method reduces environmental pollution but requires specialised equipment.

Laser Rust Removal:

• Using a laser beam to irradiate the steel pipe surface, causing the rust layer to vaporise or peel off instantly.

• Laser rust removal offers high precision, high efficiency, and non-contact operation, but the equipment cost is relatively high.

Wet Sandblasting Rust Removal:

• Using compressed air to propel fully wet abrasive onto the steel surface at high speed, removing rust, mill scale, and various corrosion products.

• Wet sandblasting addresses the dust pollution issue of dry sandblasting, but it may cause flash rust on the base metal, so a corrosion inhibitor is usually added.

Comparison of China’s and Overseas Steel Pipe Shot Blasting and Sandblasting Rust Removal Methods

• Environmental Friendliness: Overseas methods place greater emphasis on environmentally friendly rust removal techniques, such as electrolytic and laser rust removal. In China, awareness of environmental protection is steadily increasing, with growing adoption of eco-friendly rust removers and dust control equipment.

• Efficiency and Automation: Overseas rust removal methods prioritise higher production efficiency and automation, using automated sandblasting machines, laser rust removal systems and similar technologies. China is gradually introducing and independently developing high-efficiency, automated rust removal equipment.

• Cost: The cost of rust removal methods varies between China's and overseas approaches due to differences in equipment, technology, and materials. Generally, high-end overseas rust removal equipment has higher upfront costs but offers better long-term efficiency and performance. China's methods are typically more cost-effective, though ongoing improvements in equipment quality and efficiency are necessary.

In summary, both China’s and overseas steel pipe shot blasting and sandblasting rust removal methods have their own advantages. The choice of method depends on specific production requirements, cost budgets, and environmental protection needs.