Now all industries have basically reached saturation, and only high-quality products can stand out among many products. Only when the raw materials are more refined can the best effect be achieved. At present, there are many manufacturers of PPR pipes and fittings. The raw material of PPR pipes is polypropylene (random copolymerized polypropylene). The products produced with different brands of raw materials have certain differences in performance. In addition, the grades of production lines are different, and the quality of PPR pipes produced by various manufacturers varies greatly. When PPR pipes are used, they must be inspected before installation and can be used only after the quality is qualified. The selected pipes and fittings shall first have the quality inspection report of the quality inspection department, among which the pipes and fittings used for drinking water shall also have the hygienic performance inspection report of the hygiene inspection department, and then the appearance quality, pipe diameter and wall thickness of pipes and fittings shall be inspected according to GB / t 18742.2? 2002、GB/T18742. 3. National standards such as 2002 mainly test the following items:
1. Appearance of pipes and fittings. The color and luster of the pipe shall be basically the same, and the internal and external surfaces shall be smooth and flat, free of depression, bubbles and other surface defects affecting the performance, and shall not contain visible impurities; The surface of pipe fittings shall be smooth and flat, without cracks, bubbles, peeling, obvious impurities, serious shrinkage, uneven color, decomposition and discoloration and other defects.
2. Opacity of pipes and fittings. Pipes and fittings shall be opaque.
3. Pipe diameter and wall thickness of pipes and fittings. According to GB / T18742 2-2002 national standard, pipes are divided into S5, S4 and S3 according to size 2、S2. 5. S2 five series. There is a corresponding relationship between pipe series s and nominal pressure. The pipe specification is expressed by pipe series s, nominal outer diameter DN * nominal wall thickness en. It mainly tests the nominal outer diameter, average outer diameter, wall thickness corresponding to the pipe series, socket size of pipe fittings and corresponding nominal outer diameter.
4. Physical, mechanical and chemical properties of pipes and fittings. Whether hydrostatic test, melt mass flow rate, thermal stability test under hydrostatic state, longitudinal retraction rate of pipe and impact test of simply supported beam comply with the provisions of national standards, which can check the contents of material inspection report and retest report.
5. Whether the sanitary performance of pipes and fittings meets the provisions of national standards. This item can check the sanitary performance inspection report of the sanitary inspection department on pipes and fittings.
6. System suitability. After the pipes and fittings are connected, they shall pass the combined test of 8760 hours internal pressure and 5000 thermal cycles.
