Conducting quality control for 3PE composite pipes is a comprehensive process involving multiple stages and aspects. Below are detailed steps for quality control of 3PE composite pipes, covering raw materials, production processes, finished product inspection, and subsequent handling:
1. Quality Control of Raw Materials
1.1 Quality Control of Epoxy Powder, Adhesive, and Polyethylene:
Ensure that these raw materials are sourced from reliable suppliers and comply with relevant standards and specifications.
Conduct quality inspections on raw materials, including checks on physical properties, chemical composition, adhesive strength, and other key indicators.
Monitor the storage environment of raw materials to prevent moisture, contamination, or deterioration.
1.2 Quality Control of Steel Pipes:
Strictly inspect incoming steel pipes, including verification of pipe diameter, wall thickness, pipe number, manufacturer's certificate of conformity, and other information.
Inspect the steel pipe surface for defects such as scratches, dents, etc., and ensure that welds have a smooth transition with a surplus height not exceeding specified values.
Perform necessary cleaning and derusting treatments on steel pipes to improve the adhesion of the anticorrosive layer.
2. Quality Control of Production Processes
2.1 Steel Pipe Surface Treatment:
Use a preheating device to preheat the steel pipes to enhance derusting effectiveness.
Employ shot blasting equipment to thoroughly clean the steel pipe surface, ensuring the required surface cleanliness.
Conduct roughness tests on the derusted steel pipe surface to ensure that the anchor pattern depth is within the specified range.
2.2 Application of Anticorrosive Coatings:
Strictly control the spraying temperature, speed, and thickness of the epoxy powder to ensure a uniform coating without bubbles or cracks.
The application of adhesive should be uniform and without missed areas to improve the overall performance of the anticorrosive layer.
The wrapping of polyethylene should be tight and without wrinkles, ensuring the integrity and sealability of the anticorrosive layer.
2.3 Control of Forming Processes:
Strictly control process parameters such as drive line speed, steel pipe heating temperature, and heating temperatures of adhesive and polyethylene.
Conduct visual inspections on the formed anticorrosive layer to ensure no pits, bubbles, wrinkles, or other defects.
3. Finished Product Inspection
3.1 Inspection of Coating Performance:
Use an electric spark leak detector to test the anticorrosive layer for leaks, ensuring no leakage points.
Test the bonding strength, impact resistance, chemical resistance, and other properties of the anticorrosive layer.
3.2 Visual Inspection:
Conduct visual inspections on finished 3PE composite pipes, including coating color, gloss, uniformity, etc.
Check if the pipe end treatment is smooth and if the bevel processing meets requirements.
3.3 Inspection of Dimensions and Specifications:
Measure the dimensions and specifications of finished pipes to ensure compliance with design requirements and relevant standards.
4. Subsequent Handling
4.1 Pipe End Treatment:
Perform special treatments on pipe ends, such as controlling the length of the reserved end and chamfering the end face of the polyethylene layer.
4.2 Packaging and Storage:
Properly package finished 3PE composite pipes to prevent damage during transportation and storage.
The storage environment should be dry, well-ventilated, and free of corrosive gases to prevent aging or damage to the anticorrosive layer.
5. Quality Records and Traceability
Establish a comprehensive quality record system to document raw material inspections, production process control, finished product inspections, and other stages.
Implement quality traceability to ensure that the cause of quality issues can be quickly identified and measures taken for improvement when they arise.
