BS EN ISO 9080:2012 pdf download.Plastics piping and ducting systems – Determination of the long-term hydrostatic strength of thermoplastics materials in pipe form by extrapolation.
BS EN ISO 9080 specifies a method for predicting the long-term hydrostatic strength of thermoplastics materials by statistical extrapolation. The method is applicable to all types of thermoplastics pipe at applicable temperatures. It was developed on the basis of test data from pipe systems.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 1167-1, Thermo plastics pipes, fittings and assemblies for the conveyance of fluids — Determination of the resistance to internal pressure — Part 1: General method
I SO 1167-2, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of the resistance to internal pressure — Part 2: Preparation of pipe test pieces
ISO 2507-1:1995, Thermoplastics pipes and fittings — Vicat softening temperature — Part 1: Generaltest method ISO 3126, Plastics piping systems — Plastics piping components — Measurement and determination of dimensions
ISO 11357-3, Plastics — Differential scanning calorimetry (DSC) — Part 3. Determination of temperature and enthalpy of melting and crystallization
ISO 12162, Thermoplastics materials for pipes and fittings for pressure applications — Classification, designation and design coefficient
ISO 17456, Plastics piping systems — Multilayer pipes — Determination of long-term strength
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
4 Acquisition of test data
4.1 Test conditions
The pipe stress rupture data shall be determined in accordance with ISO 1167-1 and ISO 1167-2. The determination of the resistance to internal pressure shall be carried out using straight pipes.
The mean outside diameter and minimum wall thickness of each pipe test piece shall be determined in accordance with ISO 3126.
For all calculations, the pipes tested shall be of the same nominal dimension and made from the same batch of material and come from the same production run.
Forexisting materials evaluated according to ISO/TR 9080:1992 or ISO 9080:2003, the initial data set may be complemented by additional data produced from other batches to meet the requirements of 4.2. In such case, the additional data should be spread regularly at each temperature and documented in the test report.
4.2 Distribution of internal pressure levels and time ranges
4.2.1 For each temperature selected, a minimum of 30 observations shall be obtained, spread over the
testing time. Internal pressure levels shall be selected such that at least four observations will occur above
7 000 h and at least one above 9 000 h (see also 5.1.5). In the event of prediction based on the second branch,
a minimum number of 20 observations is required for the second branches, with a minimum of 5 observations
per temperature.
4.2.2 For all temperatures, times to failure up to 10 h shall be neglected.
4.2.3 At temperatures < 40 °C. times to failure up to 1 000 h may be neglected, provided that the number of remaining observations conforms to 4.2.1. In that case, at the selected temperature(s), all points below the selected time shall be discarded.
4.2.4 Test pieces which have not failed above 1 000 h may be used as observations in the multiple linear regression computations and for the determination of the presence of a knee, Otherwise, they should be disregarded, provided that the number of remaining observations conforms 104.2.1.
5 Procedure
5.1 Data gathering and analysis
5.1.1 General
The method is based on multiple linear regression and calculation details given in Annex A. It requires testing at two or more temperatures and times of 9 000 h or longer and is applicable whether or not indications are found for the presence of a knee.BS EN ISO 9080 pdf download.