All industrial mechanical refrigeration systems will have valves. Generally speaking most authorities such as IIAR would like to see a valve at the inlet and outlet of all mechanical refrigeration components for isolation. One downfall is when a facility has these valves, but they are not accessible to the ammonia technicians.
So what does the standards say about access to these valves.
Manually operated valves that are inaccessible from floor level shall be operable from on of the following:
Portable Platforms
Fixed Platforms
Ladders
Chain Operated
Note: Manually operated isolation valves identified as being part of the emergency shutdown procedure must be directly operable from the floor or chain operated from a permanent work surface.
So if you have valves that are inaccessible from one of the engineered methods list above, then you should considered enacting administrative policies and evaluate your procedures to see if they call out the cycling of any valves that would be deemed inaccessible. And if these valves exist, omit thier use from your procedures (of course through the MOC process).
