Design of pumpless fire protection installation includes nominal value for pressure and volume? 1

[jejaram]

The answer might seem obvious to some of you but this is the first time I've faced a fire protection system installation like this (without a pump), so please bear with me.

The question in the thread title (which I had to summarize due to lenght constraints)is regarding the annual performance test of the system (since there are no pumps in this one), do these pumpless system design establishes a nominal pressure and volume, so that is the one that should be considered for the churn, 100 % flow and 150 % flow, when doing the annual performance test?

If not, how is the performance test supposed to be done?

 

[LittleInch]

By pumpless I assume you mean it is fed from a third party supply like the city main?

I think you just do some flow tests and monitor pressure.

For "churn" just monitor pressure over a long period to make sure that the minimum supply pressure is actually met.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[cdafd]

1. So are you designing to NFPA 13??

2. There is no stationary fire pump as part of the system???

If yes to #2 there is no performance test to be done!

Just required stuff for the sprinkler system, per NFPA 25

Am I missing something???

 

[LCREP]

I assume you have a water supply from a public or private water main? If so you will need to conduct a water supply test.See link how to perform the test and how to use the data. You will need a pressure gauge to connect on 1 hydrant and a pitot gauge to measure the flow of water from another hydrant.

https://www1.wsrb.com/resources/hydrant-flow-testing

If you have any questions let us know. Most facilities in the USA use public water supplies for fire protection. We may you a fire pump when the public supply may have enough gpm but not enough psi hence the “booster fire pump” Sometimes the site has no public supply so a tank and fire pump are installed or if an insurance carrier is involved they may require a second water supply ie tank and fire pump.

Tom

 

[TravisMack]

You just need to follow NFPA 25. Why would you do a pump performance test when there is no pump? Your main drain test will be your test of the water supply annually.

Travis Mack, SET, RME-G,
MEPCad, Inc
AutoSPRINK | AutoSPRINK FAB | AutoSPRINK RVT

 

[jejaram]

Thanks for the answers and the link and I apologize for not being more specific.

The system I was referring to is one fed by their own water supply but just using gravity, hence pumpless. The design is correct and the amount of water and the hydraulic head are correct.

The reason to do a performance test is too guarantee that all parts of the system work correctly in case they are needed.

So what would be the required stuff for the sprinkler system, per NFPA 25?

 

[TravisMack]

Yes. You follow the inspection, testing and maintenance procedures in NFPA 25. You are not doing a performance test, however.

Travis Mack, SET, RME-G,
MEPCad, Inc
AutoSPRINK | AutoSPRINK FAB | AutoSPRINK RVT

 

[LCREP]

My experience as an insurance engineer who tested and reviewed sprinkler system reports. As indicated NFPA 25 is the NFPA document as well as any local AHJ requirements.

1. Visual and testing review of all control valves inside and outside of the building to determine if open. Sprinkler control valves closed is the number 1 reason for sprinkler system failure. Weekly to monthly inspections depending on how the valve is secured open. Testing of the valve tamper device, closing the valve 100% and reopen annually more details in 25.
2. Main drain test of the sprinkler riser to determine if the water supply has deteriorated from the previous test and the valves are open. Record static water psi, open valve record residual psi, compare to previous test. So much fun when you open the valve and the psi drops to 0 psi and does not recover indicating a closed valve. Usually the last main drain to be tested on a Friday afternoon around 4 pm. As an insurance engineer we could not leave the site until the problem was found and corrected ie open the valve. Several times the valve from the public water main to the sprinkler riser was closed. Occasionally it was the “curb box” valve the water company has the required wrench to open and close the water service to the building. So much fun getting them to come to the building on a Friday afternoon…lol.
3. Sprinkler system alarm testing for water flow, valve tamper, etc more depending on the type of system ie wet vs dry.
4. Visual on sprinklers in the building to check age, painted, obstruction, missing, etc.

All of the above is documented in a report. I always asked for 3 years of past reports to review potential problems. Interesting if the past 3 years are all different sprinkler contractors low bid may equal poor inspection. Or contractor 1 indicates a lot of problems and contractor 2 indicates none.

Hope this helps.

Tom

 

[jejaram]

Thanks a lot Tom, that seems to cover my needs