Fusible Links are to be replaced as per the mfg specs
Amerex @ 6 months intervals
Ansul 12 month ( but recommend evry 6 months)
Kiddde 6 months
Range Guard 6 months
Pryo Chem 12 month
Fusible links have the following info stamped on them:
1. the year manufactured
2. the temp rating
3. the model number (K, ML, A, B, D from Globe , or Elsie A)
Automatic bulb type detectors are the glass bulb type. These are either detectors for suppression systems or sprinkler heads. If these are kept clean, they supposedly never need replacement. Of course you do not want to hit the glass bulb. If you break the glass, the suppression system will activate.
As a further note, Ansul notes in the installation manual that the cable crimps ( found on the detector cable at the end of line detector and somtimes the series detector ) are not to be made of zinc, but brass instead. The zinc cable crimps are subject to corrosion when in contact with cleaning chemical. This can lead to un-wanted system activation. Remember this when you get blamed for tripping a system. The crimps should be made using only the correct tool, which is not vise-grips.
Fusible links come in different temperature ratings, from 135 F to 500 F. Mc Donalds specifies low temp links in some of their applications. Links also come in different load rating ranges, 3 # to 50 #. Amerex allows only K links in their systems.
Not all installations have the detectors/conduit properly secured. Loose parts may be the cause of un-wanted activations. If you find these problems, make notes, CYA.
Keep on the good side of a fire protection company, that way should you get blamed for an un-wanted system activation, you can call in your expert witness. May be the fault is not yours, but the actions of someone else. Or maybe it is your fault, it happens. When I was learning fire suppressions systems, I was told I could not claim to be an expert untill I tripped a sytem. In 24 years, I have tripped 3 systems. It was embaressing, but I made it right and kept my customers.
Douglas Hicks
General Fire Equipment Co of Eastern Oregon, Inc