ANSI/ASHRAE 15-2004, "Safety Standard for Refrigeration Systems," includes clarifications to the application of safety relief valves for pressure vessels as well as the addition of flammable refrigerant restrictions in comfort cooling applications that were omitted from the 2001 standard. In addition, references utilized in the standard were updated.

"Significant changes were made in the area of safety relief venting in the 2001 standard," Doug Reindl, chair of the Standard 15 committee, said.

"These changes led to further questions in the area of relief valve applications for larger vessels. The new standard clarifies requirements for the application of safety relief valves on larger vessels in excess of 10 cubic feet. The new wording on relief valve requirements for larger vessels removes any ambiguity."

The standard includes prohibitions against the use of flammable refrigerants for applications for human comfort. The revision was made to these requirements to correct an omission in the 2001 standard, 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.

For more information, visit www.ashrae.org.

Publication date: 01/31/2005