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. 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. Unless noted otherwise in this Standard, the requirements and standards for roof drains specified in ASME A112.6.4 do not apply to siphonic roof drains. This Standard does not apply to conventional roof drains covered under ASME A112.6.4. 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. These data are to be made available in manufacturer literature for use by designers for selecting the drain product and entering performance characteristics into design calculations.