February 1, 2016 Corroded Sprinklers "We have been using a testing laboratory for testing ESFR sprinklers that are 20 years old. The response time results are reported as "Normal" or "Failed". The problem is that they also comment on the condition of the sprinkler and use a term to describe most sprinklers as "Lightly Corroded or Loaded". This term is used when there is no visible sign of decay, but the sprinkler is discolored. Once they label a sprinkler "Corroded" we are compelled to replace the sprinklers, even though we would not consider a mildly tarnished sprinkler to require replacement provided all sprinklers in the sampling otherwise tested normal. Does the laboratory observation require the sprinklers be changed if they are tested "Normal" and the "corrosion" appears to be simply uniform discoloration or tarnishing?" We have reviewed NFPA 25, 2014 edition as the applicable standard. Our informal interpretation is that discoloration or tarnishing of brass should not be cause for replacement. There is no definition in NFPA 25 for corrosion. The dictionary should be referenced when NFPA does not define a term. The online version of Webster's Dictionary indicates that corrode is to eat away by degrees as if by gnawing; to wear away gradually usually by chemical reaction; to weaken or destroy gradually. Section 5.2.1.1.1 indicates that sprinklers shall be free of corrosion and Section 5.2.1.1.2 indicates that any sprinkler that shows signs of any corrosion shall be replaced. This taken literally indicates that sprinklers will require replacement. With that said, Annex A.5.2.1.1.2(2) does address the question. This states, "Corrosion found on the seat, or built up on the deflector that could affect the spray pattern, or a buildup on the operating elements that could affect the operation can have a detrimental effect on the performance of the sprinkler". Light surface corrosion on the boss, frame arms, and/or the deflector, or surface discoloration, not impacting the operation of the sprinkler should not warrant replacement. A degree of judgment should be exercised in the determination of the extent, location, and character of corrosion that would necessitate replacement." Thus if a sprinkler turns green, it is likely a form of corrosion and should be replaced. The commentary in the Water-Based Fire Protection Systems Handbook under Section 5.2.1.1 says that when there is a concern over whether sprinklers will perform as intended due to loading or corrosion, representative samples can be tested following the requirements of 5.3.1 to determine if replacement is warranted. It should also be noted that brass and bronze will discolor over time and such discoloration is not usually considered corrosion or loading. Although the testing laboratory may label the sprinkler as corroded, past verbal comments expressed by representatives of testing laboratories indicate that they may not test the sprinkler if it has corrosion to the point of needing replacement. The use of the terms "Lightly Corroded or Loaded" used by a laboratory could be used to address any issues regarding future litigation. Thus, this leaves one to use a degree of judgment regarding discoloration or tarnishing when addressing the replacement of sprinklers.
Click here for PDF Version Archives Technical Update is prepared by the Technical Services Dept. of the AFSA: Vice President of Engineering and Technical Services Roland Huggins, a PE registered in fire protection engineering; Phill Brown, a NICET IV certified automatic sprinkler technician and NFPA Certified Fire Protection Specialist (CFPS) and Tom Wellen, a PE registered in fire protection engineering. This is provided with the understanding that the AFSA assumes no liability for this opinion or actions taken on it and they are not to be considered the official position of the NFPA or its technical committees. Copyright 2016 American Fire Sprinkler Association. All Rights Reserved Quick Links firesprinkler.org Join AFSA Scholarships Safety Training Technical Services Informal Interpretation Request Training Calendar AFSA Beginning Fire Sprinkler System Planning School 2016 Schedule Feb. 8 - 19 April 4 - 15 May 16 - 27 July 18 - 29 Oct. 3 - 14 For more info, call: 214-349-5965 ext. 132 American Fire Sprinkler Association | 12750 Merit Drive, Suite 350 | Dallas | TX | 75251
