Expanded requirements for safety relief protection are contained in ASHRAE’s new 2007 refrigeration systems safety standard. ANSI/ASHRAE Standard 15-2007, Safety Standard for Refrigeration Systems, establishes procedures for operating equipment and systems to assure the safety of building occupants and system technicians.
A significant change over the 2004 standard is expanded requirements for safety relief protection piped internally to systems. “In the interest of keeping refrigerants contained within a refrigeration system, a growing number of designers sought to implement pressure relief protection that discharged overpressure refrigerants to a lower pressure portion of the system,” Douglas Reindl, committee chair, said. “This change is intended to guard safety in these applications by expanding requirements for the engineering of internal relief devices.”

Another change is the update of Appendix F, which outlines the principles of relief device selection for positive displacement compressors. The list of refrigerants with corresponding properties included in the appendix has been significantly expanded.

 “This will help users enhance the safety of refrigeration systems by utilizing improved methods for pressure relief protection,” Reindl said.

Standard 15 was first published in 1919 as Tentative Code for the Regulation of Refrigerating Machines and Refrigerants in recognition of the need for cities and states to enact safety regulations.