May 10 2017

5-Year Internal Inspection of Sprinkler Systems

Category: Questions and Answers,SprinklersBKeyes @ 12:00 am

Q: I listened in on your webinar when you introduced all of us to the changes with the new 2012 Life Safety Code. In regards to the section involving fire sprinklers you stated that we need to have a five-year internal inspection of the pipe at the end of the line and a branch to a sprinkler head. But you do not specify whether this applies to just wet systems or dry systems? Do we need to do this on both types of systems?

A: According to Section 14.2 (Internal Inspection of Piping) in NFPA 25-2011, here is what’s required:

  • An inspection of piping and branch line conditions shall be conducted every 5 years by opening a flushing connection at the end of one main and by removing a sprinkler toward the end of one branch line for the purpose of inspecting for the presence of foreign organic and inorganic material.

Brad’s comments: According to the NFPA handbook for this section, you must open up both locations (a flushing location and a sprinkler) and examine the condition of the pipe inside both of these locations. The standard specifically wants you to look for the presence of Micro-biologically Influenced Corrosion (MIC), zebra mussels, or inorganic materials such as rust and scale, as well as other items that may have been left in place by the installers such as gloves and cut-out coupons. You’re looking for these items because they can cause obstructions. According to the handbook, looking in just two locations once every 5 years is sufficient and provides a reasonable assurance that the entire system is acceptable. This internal inspection should be coordinated when the system is drained for other internal inspections, such as check valves. The handbook specifically says this 5-year inspection applies to wet, dry, pre-action, and deluge systems, as well as foam-water sprinkler systems.

  • Alternative non-destructive examination methods shall be permitted.

Alternative nondestructive examination methods includes the use of X-ray, ultrasound, and remote video techniques.  

  • Tubercules or slime, if found, shall be tested for MIC.

NFPA does not define what a tubercule is, but according to a dictionary, a tubercule (also spelled tubercle) is a nodule or small eminence, attached to the inside of the pipe. The reason NFPA wants tubercules and slime tested for MIC, is MIC is very destructive to the inside of a sprinkler pipe, and almost always leads to pinhole leaks. There is newer technology being used that injects nitrogen (taken from the atmosphere) into the sprinkler system when filling that lowers the level of oxygen to a point that prohibits MIC from growing.

  •  If the presence of sufficient foreign material is found to obstruct the pipe or sprinklers, then an obstruction investigation must be conducted as described in section 14.3.

NFPA does not say how much foreign material is sufficient to obstruct pipe or sprinklers, so this is a judgement call. It would be normal to observe small amounts of scale and rust inside sprinkler pipe and should not trigger an obstruction investigation.

  • Non-metallic pipe shall not be required to be inspected internally.

Corrosion is associated with metallic pipe so non-metallic pipe (i.e. plastic CPVC) is not subject to the 5-year internal inspection.

  • In dry systems and pre-action systems the sprinkler removed for inspection shall be from the most remote branch line from the source of water that is not equipped with the inspector’s test valve.

The dry system and pre-action system is required to have an inspector’s test valve, but NFPA does not want a sprinkler pulled on the branch line containing the inspector’s test valve. So, they want the sprinkler pulled on the next branch line closest to the branch line containing the inspector’s test valve.

If you haven’t already done so, obtain a copy of NFPA 25-2011 for your own reference.