ASME A112.6.9

The ASME 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 and create a full-bore flow: the flow of water in  a pipe where theoretically 100% of the cross-section of the pipe bore is filled.  In practical terms, full-bore flow is regarded as achieved at water content greater than 95% by volume.  This Standard includes 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. 

Manufacturers of siphonic roof drains may utilize existing conventional drain body designs with an air baffle adapter to achieve siphonic capability when connected to a properly engineered siphonic drainage piping system. 

The design of any air baffle and drain follows three main principles: 

Manufacturers 
 

Jay R Smith Mfg. Co.  

Josam Company

www.josam.com/pdf/loro/brochure/LoroJosam_intro.pdf

Mifab Inc.

Tyler Pipe/Wade

Zurn Industries, Inc.