From NFSA TechNotes Issue # 369 March 15, 2017
What would cause the loss of fluid in glass bulb sprinklers?
Answer: There can be several causes for the loss of fluid in a glass bulb such as damage during shipment, handling and installation in the field. From a manufacturing standpoint, UL adopted a revision into its sprinkler standards in 2003 to require glass bulb integrity testing after the sprinkler has been fully assembled and subjected to the production leakage test. This requirement became effective September 26, 2004.
This was also addressed in NFPA 25-2017 under section 22.214.171.124.1(4), which states:
“126.96.36.199.1 Any sprinkler that shows signs of any of the following shall be replaced:
(2) Corrosion detrimental to sprinkler performance
(3) Physical Damage
(4) Loss of fluid in the glass bulb responsive element
(5) Loading detrimental to sprinkler performance
(6) Paint other than that applied by the sprinkler manufacturer”
It is also advisable to contact the sprinkler manufacturer regarding such issues.