Tip #42 - Time to Replace Those Antiques!
NFPA 25-2011: 5.3.1 188.8.131.52.1.3* Sprinklers manufactured using fast-response elements that have been in service for 20 years shall be replaced, or representative samples shall be tested and then retested at 10-year intervals. A quick-response sprinkler, residential sprinkler, and early suppression suppression fast-response (ESFR) sprinklers are examples of fast response sprinklers. If your quick response heads were installed prior to 1999 make sure you have documentation of them being tested or replaced. All heads need to be tested or replaced every 50 years.
How do you know if your head is a standard response or a quick response? one of the common indicators will be that a QR head has a much smaller (3mm) bulb.