At present, there are many PP-R pipe manufacturers. The raw material of PP-R pipe is polypropylene (random copolymer polypropylene). The products produced by different brands of raw materials have certain differences in performance, and the production line grades are different. The quality of PP-R pipes produced by various manufacturers is quite different. When PP-R pipe is used, it must be inspected before installation, and it can be used only after it is qualified. The selected pipe fittings should first have the quality inspection report of the quality inspection department. The pipe fittings for drinking water should also have the hygienic performance inspection report of the sanitary inspection department, and then the appearance quality and diameter of the pipe and fittings should be checked. Wall thickness, when inspecting pipe fittings, mainly inspect the following items according to GB/T 18742.2?2002, GB/T18742.3?2002 and other national standards:
1. Appearance of pipe fittings. The color of the pipe should be basically the same, the inner and outer surfaces should be smooth and flat, no dents, bubbles and other surface defects affecting performance, and should not contain visible impurities; the surface of the pipe should be smooth and flat, and no cracks, bubbles, peeling and obvious Impurities, severe shrinkage, and uneven color, decomposition and discoloration.
2. The opacity of pipe fittings. Pipe fittings should be opaque.
3. Pipe diameter and wall thickness of pipe fittings. According to the national standard GB/T18742.2-2002, the pipes are divided into five series according to size: S5, S4, S3.2, S2.5 and S2. The pipe series S has a corresponding correspondence with the nominal pressure. The pipe specification is expressed by the pipe series S and the nominal outer diameter dn* nominal wall thickness en. The main inspection outer diameter and average outer diameter of the pipe and the wall thickness corresponding to the pipe series are mainly The size of the socket of the pipe fitting and the corresponding nominal outer diameter.
4. Physical and mechanical properties and chemical properties of pipe fittings. Hydrostatic test, melt mass flow rate, thermal stability test under hydrostatic condition, longitudinal retraction rate of pipe, and simply supported beam impact test conform to national standards. The inspection report content and retest report content of this material can be inspected. .
5. Whether the sanitary performance of pipe fittings complies with national standards. This item can be used to check the hygienic performance test report of the pipe fittings by the health inspection department.
6, system suitability. After the pipe and the pipe are connected, the test shall be carried out by combining the internal pressure of 8760 hours and the thermal cycle of 5000 times.
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