This test method provides a practical means of assessing glass pipe strength under short-duration, thermally-imposed tensile stresses. In addition to a principal role played by the linear coefficient of thermal expansion, glass surface defects can also be major factors in reducing downshock performance.

1.1 Since thermal shock resistance is so closely related to the linear coefficient of expansion, this method for the determination of the thermal shock resistance of glass process pipe is primarily intended to supplement test results on the linear coefficient of expansion, Test Method E228. This thermal shock test will not ordinarily be performed except in those cases where the thermal shock resistance may be questioned.

1.2 This method covers only two of four thermal shock possible approaches, namely independent downshock of outside and inside pipe surfaces. Downshock is more severe since a higher tensile stress is produced and, hence, more likely to produce failure.

1.3 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.