Preface:

This is the third edition of ANSI Z21.98 • CSA 4.10, Non-metallic dip tubes for use in water heaters. It supersedes the previous editions published in 2014 and 2012.

Scope:

1.1
This Standard applies to newly produced non-metallic dip tubes intended for use in water heaters.

1.2
Compliance of a dip tube with this Standard does not imply that such dip tube is acceptable for use in water heaters without supplemental tests with the dip tube installed in the particular water heater design.

1.3
This Standard contains SI (Metric) corresponding to the yard/pound quantities, the purpose being to allow the Standard to be used in SI (Metric) units. (American National Standard for Metric Practice, IEEE/ASTM SI 10, or ISO 80000-1:2009, Quantities and units — Part 1: General, is used as a guide in making metric conversion from yard/pound quantities.) If a value for a measurement and a corresponding value in other units are stated, the first stated value is to be regarded as the requirement. The given corresponding value may be approximate. If a value for a measurement and a corresponding value in other units are both specified as a quoted marking requirement, the first stated unit, or both, are to be provided.

1.4
In this Standard, "shall" is used to express a requirement, i.e., a provision that the user shall satisfy in order to comply with the standard; "should" is used to express a recommendation or that which is advised but not required; and "may" is used to express an option or that which is permissible within the limits of the Standard. Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. Notes to tables and figures are considered part of the table or figure and may be written as requirements. Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.