ASTM D2992-18 pdf free.Standard Practice for Obtaining Hydrostatic or Pressure Design Basis for “Fiberglass” (Glass-Fiber-Reinforced Thermosetting Resin) Pipe and Fittings.
1.1 Data meeting the criteria of 12.4 may be assumed to be part of the original data set and it is permitted to determine a new regression line and HDB or PDB using all failure points.Specimens which have not failed after 1200 hours or 1 800 000 cycles are not suitable for establishing a new regression line;however, it is permitted to use these points for the purpose of reconfirmation.
1.2 If the data fails to satisfy the criteria of 12.4, the changes are considered major and a new regression line must be established. While the new test program is being conducted, an interim HDB or PDB for the material or process change may be taken as the lower of the following:
1.3.1 The 95 % lower confidence limit of the value obtained by extrapolating the failure points of 12.3.1 to 657 000 000 cycles (50 years), or the failure points of 12.3.2 to 438 000 h (50 years) by the procedure in Annex A1.
1.4 The 95 % lower confidence limit of the original regression line at 50 years.
2. Hydrostatic Design Stress or Hydrostatic Design Pressure
2.1 Obtain the HDS or HDP by multiplying the HDB or PDB as determined by Procedure A or Procedure B by a service design factor selected for the application on the basis of two general groups of conditions. The first group considers the manufacturing and testing variables, specifically normal variations in the material, manufacture, dimensions, good handling techniques, and in the evaluation procedures in this method.The second group considers the application or use, specifically installation, environment, temperature, hazard involved, life expectancy desired, and the degree of reliability selected.
2.2 For data based on hoop stress calculate the pressure rating from the HDS by means of the ISO equation in 3.1.8 for each diameter and wall thickness of pipe made from the specific materials and constructions tested.
2.3 For data based on internal pressure, establish the pressure rating directly from the HDP for products made from the specific materials and constructions tested.ASTM D2992 pdf download.