Draft Details

Designation:B79.9
Source:CSA
Review start date:Jul 9, 2021
Review end date:Sep 7, 2021
Contact email:mary.morgan(at)csagroup.org
Draft Scope/Description:

1 Scope

This standard establishes minimum requirements and provides guidelines for the proper design, installation, examination, and testing of siphonic roof drains.  It includes definitions of terms and parameters involved in the proper design of siphonic drainage systems.

It is not the intent of this Standard to specify that a drain of a given diameter must drain a minimum or maximum amount of water.  It is the intent of this standard to provide standardized test procedures to ensure that drain products are evaluated equally.

This Standard does not dictate minimum flow or depth performance criteria for siphonic roof drains.  Instead, it specifies standard test procedures to be performed on siphonic roof drain products to document their actual performance and physical limits.  This data is to be made available in manufacturer literature for use by designers for selecting the drain product and entering performance characteristics into design calculations.

1.1 Inclusions

This standard applies to roof drains designed, manufactured, and installed in piping systems that are intended to operate under depressurized siphonic conditions created by the connected piping system.

1.2 Exclusions

1.2.1 Applicability of roof drain standards

Unless noted otherwise in this Standard, the requirements and standards for roof drains specified in ASME A112.6.4/CSA B79.4 do not apply to siphonic roof drains.

1.2.2 Conventional roof drains

This Standard does not apply to conventional roof drains covered under ASME A112.6.4/CSA B79.4.

1.3 Terminology

In this Standard, “shall” is used to express a requirement, i.e., a provision that the user is obliged to 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.

1.4 Units of measure

The values given in either SI (metric) or U.S. Customary units of measure are equivalent in application; however, each measurement system is to be used independently of the other.  In this Standard, U.S. Customary units are shown in parentheses.  Combining values from the two measurement systems can result in non-conformance with this Standard.

1.4.1 U.S. Customary units

All references to gallons are to U.S. liquid gallons.

1.5 Alternatives

The requirements of this Standard are not intended to prevent the use of alternative designs, materials, or methods of construction, provided such alternatives meet the intent and requirements of this Standard.

You may comment on any section of this document by clicking the “Submit Comment” link at the bottom of the relevant section.