1. Resin

The unsaturated polyester resin used should comply with the provisions of GB/T 8237.

OD Series RPM Tube Sizes

The epoxy resin used should comply with the provisions of GB/T 13657.

The resin hygiene standards for piping used as water supply and drinking water pipes must comply with the requirements of GB 13115.

2. Enhanced Material

The glass fiber yarns used, both alkali-free and untwisted, as well as medium-alkali untwisted glass fiber yarns, should comply with the provisions of GB/T 18369-2008.

3. Filling Material

SiO2 content should be greater than 95%, moisture content should be less than 0.2%.

CaCO3 content greater than 98%, moisture content should be less than 0.2%.

4. Appearance Quality

The inner surface of the pipe should be smooth and flat, free of cracks, delamination, pinholes, impurities, under-gelled areas, and bubbles. The end face of the pipe should be even and free of burrs. The outer surface of the pipe should have no obvious defects.

5. Dimensions

Diameter Tolerance: The outer diameter series should comply with the specifications in Table 1, and the inner diameter series should comply with the specifications in Table 2.

Length Tolerance: ±0.005L (L being the effective length of the tube).

Wall thickness: The minimum thickness should not be less than 87.5% of the nominal thickness specified in the approved drawings and technical documents, and the average thickness should not be less than the nominal thickness.

End face perpendicularity: In compliance with the specifications in Table 3.