1.1 This test method covers the determination of load-deflection characteristics of plastic pipe under parallel-plate loading. 1.2 This test method covers thermoplastic resin pipe, reinforced thermosetting resin pipe (RTRP), and reinforced polymer mortar pipe (RPMP). 1.3 The characteristics determined by this test method are pipe stiffness, stiffness factor, and load at specific deflections. 1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. Note 1—While this test method can be used in measuring the pipe stiffness of corrugated plastic pipe or tubing, special conditions and procedures are used. These details are included in the product standards, for example, Specification F405. 1.5 The text of this test method references notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the test method. 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 and health practices and determine the applicability of regulatory limitations prior to use.