1. Clean-Up
- Solvent Cleaning: Use organic solvents to clean the surface of seamless pipes, removing oil, grease, dust, lubricants, and similar organic compounds. This method does not remove rust, scale, or other corrosive substances and is typically used as an auxiliary step in anti-corrosion processes.
- Common Lubricants: Lubricants such as soap or cooking oil are used in the cleaning process.
- Cleaning Methods:
Preparation: Ensure the seamless pipes are free of burrs at the pipe ends before cleaning.
Projectile Cleaning: Use a hard pipe nozzle to send two clean projectiles through the pipe for initial cleaning.
Breaking Up Contaminants: For contaminants like hydraulic oil or vegetable oil, use a hard pipe spring wheel. For rust and weld marks, use a friction spring wheel.
Grinding: Utilize a grinder multiple times if necessary to ensure all contaminants are removed.
Final Cleaning: After using projectiles or friction bombs, ensure cleanliness with a final clean projectile.
Assembly Process: It's recommended to clean the pipes before the assembly process. If cleaning after assembly, use a clean spring wheel. Ensure there are no steps at the joints.
2. Anti-Rust Treatment with Special Tools
- Surface Polishing: Use special tools to polish the surface of the seamless pipes, removing loose or lifted scale, rust, and weld penetration.
- Tool Grades:
Hand Tools: Can achieve Sa2 level rust removal.
Powered Tools: Can achieve Sa3 level rust removal.
3. Pickling and Passivation
- Methods: Utilize chemical and electrolytic methods for pickling. For pipe corrosion prevention, chemical pickling followed by passivation is used.
- Benefits: Removes oxide scale, rust, and old coatings. Sometimes used as a pre-polishing step.
- Limitations: Chemical water treatment can achieve cleanliness and surface roughness but may result in shallow anchor lines and environmental pollution.
4. Spray (Throwing) Anti-Rust Treatment
- Process: A high-power motor drives a spray (throwing) blade to rotate at high speed, propelling wear-resistant materials (e.g., diamond sand, steel balls) against the pipe surface.
- Results: Effectively eliminates rust, oxides, and waste, while achieving necessary surface roughness under the impact and friction of the wear-resistant materials.
- Applications: Seamless pipes, with their hollow cross-section, are used for transporting liquids such as crude oil, gas, liquefied gas, water, and some solid raw materials.
By following these steps, the surface of seamless pipes can be effectively cleaned and prepared for various applications, ensuring optimal performance and longevity.