UK’s HSE provides some EXCELLENT guidance on how ammonia refrigeration process safety can be managed. We have always taught our process safety courses with the underlying philosophy of process safety as PREVENT, PROTECT, MITIGATE, and in this HSE material they follow the same philosophy. This information is particularly helpful as they have matched up the FAILURE MODES with the PREVENT, PROTECT, MITIGATE measures specific to an ammonia refrigeration process. This tool could be helpful for facilities when they review their PHA’s every five (5) years; it could act as a “verification” of sorts that the PHA is utilizing the Hierarchy of Controls and Layers of Protection properly. Here is their material:
PLEASE NOTE that the RAGAGEPs they reference may NOT be applicable outside the United Kingdom.