This practice describes the procedure for accelerating the crystalline phase transformation of polybutylene from the metastable Form II to the stable Form I by application of hydrostatic pressure in a closed pressure vessel.

Formerly under the jurisdiction of Committee F17 on Plastic Piping Systems, this practice was withdrawn in August 2005. This practice is being withdrawn because polybutylene piping products are no longer manufactured in North America.

1.1 This practice describes a procedure for accelerating the crystalline phase transformation of polybutylene from the metastable Form II to the stable Form I by application of hydrostatic pressure in a closed pressure vessel.

1.2 The technique can be used as an alternative to the 10-day conditioning procedure called for in Specification D 2581. The product obtained after pressure aging will be in a crystalline state, approximately that obtained by aging under Standard Laboratory Conditions.

1.3 This practice is not to be used for qualification of an extruded product for pressure rating of pipe or tubing.

1.4 The values given in parentheses are provided for information purposes only.

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. Specific precautionary statements are given in 5.2 and 6.2.