ASTM D2992-18

5.1 This practice is useful for establishing the hoop stress or internal pressure versus time-to-failure relationships, under selected internal and external environments which simulate actual anticipated product end-use conditions, from which a design basis for specific piping products and materials can be obtained. This practice defines an HDB for material in straight, hollow cylindrical shapes where hoop stress can be easily calculated, and a PDB for fittings and joints where stresses are more complex.

5.2 To characterize fiberglass piping products, it is necessary to establish the stress versus cycles or time to failure, or pressure versus cycles or time to failure relationships over three or more logarithmic decades of time (cycles or hours) within controlled environmental parameters. Because of the nature of the test and specimens employed, no single line can adequately represent the data. Therefore, the confidence limits shall be established.

5.3 Pressure ratings for piping of various dimensions at each temperature may be calculated using the HDS determined by testing one size of piping provided that the same specific process and material are used both for test specimens and the piping in question.

5.4 Pressure ratings at each temperature for components other than straight hollow shapes may be calculated using the HDP determined by testing one size of piping provided that (Note 8: Scaling of fittings and joints should be further verified by short-time testing in accordance with Test Method D1599.

5.5 Results obtained at one set of environmental conditions shall not be used for other conditions, except that higher temperature data can be used for design basis assignment for lower application temperatures. The design basis shall be determined for each specific piping product. Design and processing can significantly affect the long-term performance of piping products, and therefore shall be taken into consideration during any evaluation.

5.6 This practice is valid for a given pipe or fitting only so long as the specimens are truly representative of that material and manufacturing process.

1.1 This practice establishes two procedures, Procedure A (cyclic) and Procedure B (static), for obtaining a hydrostatic design basis (HDB) or a pressure design basis (PDB) for fiberglass piping products, by evaluating strength-regression data derived from testing pipe or fittings, or both, of the same materials and construction, either separately or in assemblies. Both glass-fiber-reinforced thermosetting-resin pipe (RTRP) and glass-fiber-reinforced polymer mortar pipe (RPMP) are fiberglass pipe.

1.2 This practice can be used for the HDB determination for fiberglass pipe where the ratio of outside diameter to wall thickness is 10:1 or more.

1.3 This practice provides a PDB for complex-shaped products or systems where complex stress fields seriously inhibit the use of hoop stress.

1.4 Specimen end closures in the underlying test methods may be either restrained or free, leading to certain limitations.

1.5 The values stated in inch-pound units are to be regarded as the standard. The values in parentheses are given for information purposes only.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.