I am reviewing a building under construction for a client, specifically the wet sprinkler system installation.

There was a problem where the installer left caps off the pipe both on pipe being stored and pipe installed at the ceiling. My client stated concerns about debris falling into the pipe due to other trades doing work in the area and requested that the sprinkler installer perform corrective measures, they proposed using compressed air to blow out the pipe.

The client wants them to provide some type of justification, industry standard or NFPA guidance that says this is an acceptable means.

I looked in NFPA 13 and NFPA 25 and only found how to deal with in-service systems that have obstructions.

Has anyone dealt with a similar situation or know what the industry standards are for cleaning out pipe during the construction phase?

​​​​​​​​​​​​​​​​​​​​​​Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe

I am a Fire Protection Engineer in Victoria working in a sugar refinery where we are proposing to protect existing raw sugar and white packaging storage. The raw sugar storage has piles of unrefined sugar in the warehouse which often clogs the sprinklers (like all other equipment in the area).

My advice to the client was more strict inspections and maintenance in this area, as well as to place metal guards to try and minimize buildup around the sprinklers.

The white packaging storage, although not as dirty as the raw sugar storage, has fine dust particles throughout. I'm not as concerned about this area.

We are not trying to re-invent the wheel here, and I'm sure there has been many acceptable solutions to minimize building on sprinklers.

What would you recommend to the client here to minimize the buildup?

​​​​​​​​​​​​​​​​Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe

Is a pumper truck from the fire department required to do standpipe flow testing?

​​​​​​​​​​Sent in anonymously for discussion. Discuss This | Submit Your Question | Subscribe

My question is when the discussion of dirty sprinkler heads comes up I get told only lint , hair and fuss count.

What I see quite often is discoloring from what I assume oil running down the pipe to the head. I also often see the red glass turned to black or gray.

Do these sprinklers need to be cleaned, and if so, how is it done?

​Air or vacuumed doesn’t always work.

​​​​​​​​​​​Sent in anonymously for discussion. Discuss This | Submit Your Question | Subscribe

We have an account that failed the five year FDC hydrostatic test. The Fire Department Connection is a remote, freestanding FDC. The Fire Marshal is claiming that there is no leakage, however, will not give a pass or fail. 

NFPA 25 (2017) and others reference hydrostatic tests.

6.3.2.1  hydrostatic test 200 psi for 2 hrs or at 50 psi in excess of the maximum pressure where maximum pressure is in excess of 150 psi every five years. (manual standpipe systems and semi-automatic dry standpipe systems, including piping in the FDC)

Annex  6.3.2.1* that mentions a minimum leakage existing under test pressure.

Section 13.8.5 FDC five year hydrostatic testing shall be tested at 150 psi for 2 hrs. There is no mention of minimal leakage allowed.

What is this allowable leakage?

NFPA 24 (2010) Private Fire Mains & Their Appurtenances Section 10.10.2.2.1 requires 200 psi or 50 psi in excess of the system working pressure whichever is greater and maintain that pressure at +/-5 psi for 2 hrs.

Is that my allowable leakage, so that if we lose less than 5 psi or gain no more than 5 psi for 2-hours, that we pass? Wasn't sure if the existing 5-year hydrostatic for underground has leakage that is measured differently from an inside hydrostatic test.
 
Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe

Recently had a job with a wet-pipe fire sprinkler system (smaller project) that has a 6-inch double check backflow. The area static and residual pressures are pretty consistent (had a flow test of ~40 psi static and ~38 psi residual at 1,300 gpm).

We ran a forward-flow test through the backflow preventer, needing a minimum flow of about 800 gpm, which includes the hose allowances for the project (no standpipes or interior hose connections).

The most flow we could get was about 450 gpm, even with three 2-1/2" hose outlets completely wide open. The static pressure following the test at the riser was about 40 psi. We used three 100 ft, 2-1/2" hoses with a 1-3/4" smooth nozzle and diffusers at the end of each hose, measuring about 3 psi pitot on each and full flow (which equates to roughly 450 gpm).

Do you have any tips or advice in why we were not able to get enough flow through the backflow, or where to start to troubleshoot?

Thanks in advance!

​​​​​​​​​​​​​​​​Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe

In an existing building utilizing a “booster pump” or unlisted fire pump for a standpipe or sprinkler system, is there a suggested annual flow test procedure?

I realize there is no manufacturer’s data (0%,100%,150% rated capacity) to compare the results against.

Should it be excluded from the annual flow test requirements, and just flowed during the 5 year roof top flow?

I would appreciate input as well as, what others in the industry are doing to address this fairly common scenario.

​​​​​​​​​​​​​​​​Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe

Does anyone have any pressure maintenance pumps installed on their sprinkler systems without having a fire pump?

In other words, having a pump on the sprinkler system that is only there for the purposes of preventing a false alarm (due to pressure ebbs and spikes in the water supply) instead of boosting the water pressure like a traditional fire and jockey pump combination.

We have some legacy jockey pumps installed like this and it runs into a grey area for maintenance as they don't affect the performance of the sprinkler system they are connected to. Any thoughts?

Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe

I have an inspection question regarding quarterly checks on low air supervisory devices on dry systems.

Is it okay to simply "jump off" the device when not doing a full or partial trip to simply make sure it hits the panel?

I feel like I'm doing a disservice inspecting using this method, but I've seen it a lot. Unfortunately for me, it's been a crapshoot lately on what dry valve is going to go haywire when I drop air via an Inspector's Test Valve or at the riser. I'm thinking of just recommending a bleeder valve to be installed and go the easy route, saving both myself and customers a lot of anxiousness.

​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe

NFPA 25 requires a legible Hydraulic Information Sign.

How do I replace a missing Hydraulic Placard (or calculation plate/card) on an existing system? And what if there isn't original design information available?

I'm curious to see how others are addressing this deficiency.

​​​​​​​​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe

Looking for guidance on pressure gauge selection. Is there a requirement for a maximum pressure gauge for testing residual pressures of 40-50 psi on suppression systems?

Wondering if any pressure gauge is adequate or if there's specific guidance I should be following on gauge selection.

Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe

When testing a fire pump from the roof is there a calculation that is necessary to ensure that the flow test is accurate (given pipe sizes, elevation increase, etc)?

NFPA 25, 2014 handbook states that flowing from the roof in the explanatory material is somewhat acceptable (NFPA 25, 2014: 8.3.3.1.3). However, NFPA 20, 2013 A.4.20.3.4(2) has a sample hydraulic calculation sheet for sizing the test header when not using the table which appears to take into account items like friction loss, elevation, etc.

​​​​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe