Every refrigeration system shall be protected by a pressure relief device. Soft soldered joints, rubber or synthetic gaskets, or fusible plugs shall not be considered relief devices meeting the requirements of this article. All pressure devices shall bear the label of an approved agency. The device shall be rated for the capacity of the refrigerant system. The pressure relief device shall be rated for the capacity of the refrigerant system. The pressure relief device shall be set at the maximum design pressure of the system or equipment.
Absorption systems employing a steam coil in the generator of the system must be provided with an approved pressure relief valve in the steam piping, located as near as practicable to the generator and other vessels in the system. The capacity of such pressure relief valve shall be based on the total possible energy that can be imposed on the absorption system.
Exception: Refrigeration systems that are UL 1995 approved and contain: Less than 6 pounds of a Group 2 Refrigerant, or 30 pounds or less of a Group 1 refrigerant do not require a pressure relief device.