How Often to Re-Test Loaded Sprinklers?

1/15/2025

In NFPA 25-2017 Chapter 5 addresses "Loaded sprinklers." Of course, this has been a "LOADED" question for years and everybody's interruption of what that is whether or not NFPA gives a decent explanation of it.

My question is, we have a customer that we've performed a sprinkler test by removing an X amount of sprinklers and sending it away to a third party lab for testing which samples came back as a pass - but the question has come up asking if sprinklers remain to be loaded the same if not more over the years.

What would be the timeline for re-testing?

Would it follow the 10 year re-test?

Or 5 Year sprinkler testing that NFPA 25 requires for sprinklers in "hazardous" environment areas?

As this plant has over 600 sprinklers and getting up to them and cleaning them every year is not practical, that option is not on the table. See NFPA 25-2017 code for the discussion on it.

Thanks for your take.

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10 Comments

Matthew

1/15/2025 08:24:58 am

5.3.1.1.2*
Where sprinklers are subjected to harsh environments, including corrosive atmospheres and corrosive water supplies, on a 5-year basis, either sprinklers shall be replaced or representative sprinkler samples shall be tested.

A.5.3.1.1.2
Examples of these environments are paper mills, packing houses, tanneries, alkali plants, organic fertilizer plants, foundries, forge shops, fumigation areas, pickle and vinegar works, stables, storage battery rooms, electroplating rooms, galvanizing rooms, steam rooms of all descriptions including moist vapor dry kilns, salt storage rooms, locomotive sheds or houses, driveways, areas exposed to outside weather, around bleaching equipment in flour mills, and portions of any area where corrosive vapors prevail. Harsh water environments include water supplies that are chemically reactive.

It sounds like the environment fits the description of a harsh environment and will need to be tested or replace every 5 years for however long the harsh environmental condition exists.

Andrew

1/15/2025 06:05:30 pm

I find it curious how the appendix calls out locomotive diesel shops (or just storage, by the plain wording) as harsh environments but not highway truck diesel shops or garages.

Matt C

1/15/2025 08:38:43 am

It's worth noting the following from the appendix notation:
"Severely corroded or loaded sprinklers should be reported
as a deficiency or impairment as part of the visual inspection
and designated to be replaced. Such sprinklers could be affec‐
ted in their distribution or other performance characteristics
not addressed by routine sample testing."

Unless I'm missing something, the standard doesn't specifically allow for loaded sprinklers to be tested instead of simply replaced. (5.2.1.1.1.)

Glenn Berger

1/15/2025 08:43:55 am

Recommend following NFPA 25 for the guidelines based on sprinkler types / locations / hazardous / etc.

Dan Wilder

1/15/2025 09:56:44 am

Just for clarification, are they pulling and testing the loaded sprinklers (i.e. using a cleaning method not available for the installed sprinklers)?

Over the years, loaded has tended to be centered around debris on the thermal elements and deflector...the base, frame arms, and top of deflector has had more allowance for accumulation.

The loaded sprinklers are a deficiency that would need to be addressed via either non-invasive/corrosive cleaning methods like air or replaced. Testing is an entirely different section that is independent of deficiencies found.

Being a "plant" does not trigger the "Hazardous" environment, and likely would not extend over the entire footprint. What is the occupancy? Where are the hazardous areas (heavy dust producing, large thermal variations, exposure to off-gassing due to processes) as those should be a part of the testing group along with the non-hazardous areas that fall into the installed lifespan requirements.

Justin Smith

1/15/2025 10:56:44 am

Thanks for the reply Dan, This "Plant" is a manufacturer of plastics. It has come to the insurance company attention that the HVAC in the building is being reviewed to determine if they can decrease the resins that may lift toward the ceiling. This is my worry that sprinklers are not just loaded with "dust" but whatever chemicals are being used from the manufacturing process is what's possibly loading them.

1/15/2025 12:13:33 pm

So there will be possible corrosion issues but it's not going to be apparent until the changes to the HVAC are in place. There could be an argument for a proactive change out of sprinklers in key areas (already prone to issues) to a corrosion resistant type (White Poly, Wax Coating, PTFE coating or even bagging but that would require changing the bags out as needed).

Loading is checked upon annually (minimum) so hopefully any changes become apparent. Maybe provide monthly/quarterly visual inspections, or teach the maintenance guys how to do it, for the sprinklers to identify worsening issues...cheaper than most of the options.

James E Art Fire Protection Engineer (FPE)

1/15/2025 12:17:19 pm

For Paint booths sprinklers have long been protected by thin bags to prevent paint spray.
The bags are replaced when noticeable accumulation.

Is that just practice, or is it in the code?

Mark Harris

1/15/2025 04:23:42 pm

NFPA 33 requires the bags on sprinklers. Defines the material.

Maybe something has changed but I did not think cleaning loaded sprinklers was an option. Other than perhaps cobweb dust on a sprinkler near a diffuser.

Not sure who you send to sample test but in past life remember UL sometimes rejecting sprinklers for testing because of loading or corrosion.

Lots of good comments and discussions above. Based on hazard description five years of additional plastic loading before next test may be too long but eyes in the field would be big part of that judgment.

Jack G

1/15/2025 04:39:54 pm

Glenn s advice is spot on
Nfpa 25 calls for 1 % of the sprinklers in a sample area to a minimum of 4.
The annex provides language that the sprinklers should first be inspected visually from the floor ( 5.2.1.1.1) for signs of leakage or corrosion, paint, loss of fluid in the bulb. ( i have my men use binoculars) ( which works well). The intent is to not send sprinklers that pass a visual inspection.
The " sample areas " can be determined by the AHJ.
buildimg owner or both ( with the contractor)
An example would be a 10 story buildimgvwith 100 sprinklers per floor. If this is chosen as 1 samole area then 10 sprinklers (1%) are tested. If any fail then the owner is replacing 1000 sprinklers.
Now in the same building we could break it down into 10 sample areas. ( each floor). In this example the minimum is applied-- of 4 sprinklers per floor ( 40 total ) now if one of the test groups has a failure, then the owner only has to replace 100 sprinkkers ( even though he is paying for additional sprinklers, in groups, to be tested)
Be sure to involve the AHJ and building inspector in determining the sample areas.
So the sample area detrrmination is key.

How Often to Re-Test Loaded Sprinklers?

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