As I am sure you know, the fusible link is what automatically activates the fire suppression system. Don't worry about cleaning the links, the fire suppression system service agency should be changing those when the system is serviced, at least every 6 months.You may be able to see the date stamped in the link. The date will be a letter code, A<B<C and the date,99 for 1999, 00 for 2000, 01 for 2001. Of course, usually the amount of grease will obscure the date. If the dates, when visible, show the links have not been changed, you may want to rethink your relationship with that service agency. We call those people "Rag and Taggers", meaning if they have a rag and service tag, they can service anything, and cheaper than anyone else. Don't worry about cleaning the link itself, but the link housing should be reasonably clean. Before hitting the link housing, make sure it is supported on both ends, particulary the housing at the end of the detctor line. A loose housing can flop around, and may trip the system, or so I'm told. I only know of one time when hood cleaners tripped a system. That was probalbly because they were using steam. Links also have a temperature stamped in them. Most links are 350F, 360F or 450F. Chinese and charbroilers usually have 450F, some mcDonalds may have 235F. If you think the grease is difficult to clean, try cleaning up after an Ansul R101-30 dumps 30 # of dry chemical in the kitchen. We always dis-arm the system prior to cleaning, but then we also service the fire suppression system when cleaning. A 0 degree nozzle would blast grease off the link housing, but I am not sure what that would do to the link itself. I use a 15 degree nozzle most of the time, even on Chinese Hoods. If the owners will allow you to clean the hood as often as needed, you will probably be able to get even the link housings clean.
Douglas Hicks
General Fire Equipment Co of Eastern Oregon, Inc
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