1. The opacity of the head cap. Pipe fittings should be opaque.
2. Whether the sanitary performance of the head cap meets the national standards. This item can be used to check the sanitary performance inspection report of the pipe and fittings by the sanitation inspection department.
3. Applicability of the head cap system. After the pipe is connected with the pipe fittings, it shall pass the combined test of 8760 hours of internal pressure and 5000 thermal cycles.
4. The physical and mechanical properties and chemical properties of the head cap.
5. Appearance of the head cap. The color of the pipe should be basically the same. The inner and outer surfaces should be smooth and flat, free of dents, bubbles and other surface defects that affect performance, and should not contain visible impurities; the surface of the pipe should be smooth and flat, and cracks, bubbles, peeling and obvious are not allowed. Impurities, severe shrinkage, uneven color, discoloration and other defects.
