KS M ISO 8521-2019 Plastics piping systems — Glass-reinforced thermosetting plastics(GRP) pipes — Test methods for the determination of the apparent initial circumferential tensile strength
2022KS M ISO 8521:2022 Glass-reinforced thermosetting plastic (GRP) pipes — Test methods for the determination of the initial circumferential tensile wall strength
2019KS M ISO 8521:2019 Plastics piping systems — Glass-reinforced thermosetting plastics(GRP) pipes — Test methods for the determination of the apparent initial circumferential tensile strength
2004KS M ISO 8521:2004 Plastics piping systems-Glass-reinforced thermosetting plastics(GRP) pipes-Determination of the apparent initial circumferential tensile strength