1.1 This standard is applicable to glass reinforced plastic (GRP) pipes and pipe fittings made through low-pressure contact forming and filament wound forming.
1.2 The intermediate and lower pressure contact forming, specified in this standard, includes single-side non-pressure or low-pressure forming, as well as the wound method of textiles, nonwoven fabric and blanket under low-pressure. The standard is not applicable to the methods and products of pressure forming and semi-dry forming.
1.3 In this standard, fibre glass and unsaturated polyester resin combination is used as reference material, and other material may feasible.
HG/T 21633-1991 The following standards are cited：
