Water Flowing Methods

[Dormer1975]

I just did a pump test for a large cherry processing facility and during the test thought to myself, "there has to be a better way to do this". I am referring to controlling the flow of water out the test header. I used 2 1-3/4 inch stream straighteners and 2 fire hoses attached to 2-1/2 inch "Hose Monsters". Flowing over 2,250 gpm I quickly created a lake in their gravel parking lot and gouged a 1 foot deep creek.

While the affects of the test were fine with the company in question(they had a scraper to fill in the spaces caused by the water flow), it seems there should be easier and more efficient ways to control the water damage. The only thing I could see changing is getting rid of the stream straighteners for 2 more "Hose Monsters". I have run across the same issue flowing fire hydrants.

I just wanted to get this out to receive some input on what practices you my fellow colleagues are utilizing. Any suggestions?

 

[LCREP]

I did a flow test today on a 1500 gpm pump had no problem getting 2250 gpm with 2 hose monsters with 2.5" openings. I do not understand why you used the stream straighteners if you had the hose monsters. Take out the 1.75 inserts and let the water flow, much faster to do it with 2 hoses instead of 4. Use a shorter hose, I used 2- 20' lengths, makes the job fast and less work too.

 

[FFP1]

Playpipes attached to a truck rack or trailer which are fixed in place at the correct angle (>30 degrees in my opinion) works well. The water comes down like rain and does no damage.

If you are in a tight area and cannot discharge into a large open area, use the hose monsters (if you must) in a parking lot or try placing sheets of plywood (or other solid material) on the ground to displace the water discharge from the hose monsters.

In my experience, using hose monsters or any other device other than playpipes or a properly calibrated flow meter (calibrated using playpipes of course) is not a good idea when conducting fire pump flow tests. Playpipes provide laminar water flow which results in accurate flow rates. Using hydrant butts and/or hose monsters can lead to incorrect flow rates and affect the legitimacy of the test results.

I am a nice guy and I do not mean any disrespect to anyone reading this post; however, I would like to step up on the soap box to make a point regarding this issue. Please understand, I am not implying anything about Iaxon or LCREP (I do not know anything about Iaxon and I am very impressed with the previous comments LCREP has made on this forum), but I would like to add one more statement as food for thought for all of the readers on this forum: There is a lot more to a fire pump flow test than just obtaining the churn, 100% and 150% numbers.......I make this statement because in my 16+ year career I have come to the conclusion that many fire protection contractors fail to test or verify many of the "other" important issues when testing a fire pump. Considering how important fire pumps are to most fire protection systems (heart of the system) and the liability these contractors are assuming when fire pump flow testing is performed by their employees; it boggles my mind that so many contractors continue sending unqualified employees out to conduct fire pump flow tests. Personally, I do not think contractors should perform fire pump flow tests if the company does not possess the proper equipment or have adequately trained employees. One busted underground main or seized shaft during a fire incident could result in a law suit which either leads to astronomical liability insurance rates or possibly even result in the company going out of business due to gross negligence. Just something to think about.

 

[stookeyfpe]

FFP1

I tend to agree with regards to fire pump testing. I require at least 5-7 data points on acceptance and maintenance testing. I don't know how many times I've had fire protection contractors or pump suppliers poo-poo my testing protocol. I am a freak for calibrated pressure gauges and "amprobes" and require clear documentation showing the calibration is valid. I had one guy who was trying to control the water flow through the isolation valve to the test header rather than valves on the header itself. I was so p___ed I stopped the test, took a lunch break, and started the test after lunch. Needless to say some folks missed airplane flights but everyone understood that as the engineer of record, we would play by my rules.

Since you opened this discussion, I am also amazed when everyone looks at me when I perform a water supply test before the pump test. Water supplies are based on many variables and I'm a fanatic about testing these everytime I visit a site to get some historical perspective.

TravisMack and others, do you have some thoughts on this thread?

FFP1, I've read some of your responses and I appreciate you being candid. I've talked on the phone with InspLCRep and he is a reasonable individual who will probably agree with you.

This a great forum for engineers and design professionals. Keep up the good work folks.

 

[gouveia]

Two issues.

First to Ixaon's post about a better way. I personnaly always require a flow meter loop. That way no water is required to be flowed except during commissioning and the 5-year test. I know some people do not like the flow meters, but I believe that properly calibrated they are quite accurate. And I don't argue that flowing water is better, but a flow meter loop meets NFPA criteria.

Second, I could not agree more about lack of knowledge/experience by people testing fire pumps. Common issues I have encountered are:
1. Why can't we use the uncalibrated "sprinkler" guages?
2. Why do you need a certified pump curve from the factory?
3. Why do we need equipment to check the voltage/RPM etc?
4. Why do we need to start and stop the pump so many times?

 

[TravisMack]

Stookey:

I have not always run a hydrant flow test prior to a pump test, but, if the water supply is in question, then I do it. I figure that the pump test will give me the flow test information if I am flowing water and not running through a test meter. But, I do agree that it is a good policy to do so, if the jurisdiction will allow it.

I am wondering about your concern for throttling the flow from the test header control valve instead of the individual valves outside. I have seen this done almost exclusively in the last 6-7 years. When we needed to get water flowing, the fitter at the hoses would open up 2 valves on the test header wide open. He would then stand at the hose monsters and read the pitots. We would be in radio communication and then increase or decrease the volume to get the flow required. For the next point, we may open another hose valve or just further open the main test header valve further. This process would continue throughout the test. I have had Factory Mutual guys witness this procedure and not have an issue. Since I respect your opinion, I am interested in what the concern is with doing the throttling inside vs outside? I don't do many tests any more, but have many contractors ask me how to do them. I want to make sure to give them adequate information.

Also, I am very adamant about calibrated gauges. If the gauges aren't accurate, you may as well not even do the test! You won't be getting accurate information.

I further agree on the multiple point test. I think 5 points should be done at a minimum. It gives you the truest curve. I have always strived for churn, 50%, 100%, system demand, 150%

 

[LCREP]

Fire Pumps Testing do not get me started, as an insurance person I see EVERYTHING and I am asked to accept many a pump test that does not meet NFPA 25. Background, we used to conduct fire pump tests as an insurance company for our clients. I personally would do 50-60 pump tests a year. We had/have hose monsters and all the equipment to do a test. A few years ago we made a corporate decision to just witness the test, best thing we ever did. I also teach a 1 day and two day fire pump seminar which includes actually flowing water, so it is very hands- on, if you need more info PM and I will send you info on the classes.

My 2 cents what I see in the area I cover NJ and NYC.

1. Some contractors do not take RPM, amps/volts, readings.
2. With an emergency transfer switch with a back up generator, some do not test the switch at full flow conditions i.e. 150% gpm at 65% os psi of the pump on the generator.
3. NYC FD does NOT require annual fire pump tests!!!
4. Few use calibrated gauges.
5. Few provide a graph of the test results, and if they do they graph the wrong numbers.
6. Many indicate the fire pump is operating properly, even if it does not since they do not graph the pump test.
7. Few calculate max amps/volts and service factors to determine if the electric motor is OK.
8. Very few do a combined curve with the pump AND water supply to see if the water supply with the fire pump is adequate to meet sprinkler/standpipe demands.
9. Many miss the locked current requirements for the six times map amps of the fues/breakers in line.
10. Few adjust the casing relief valve, so the pump churns hot.
11. Many do not grease the bearings.

Anyway I can go on on and on, you get my point.

I dislike a flow meter around the pump, many are not calibrated, few know how to use them. AND NFPA 25 still requires you to flow water every 3 years to insure a valve is not closed on the suction side, which we do find.

Bottom line contractors are sending folks out who do not know what they are doing. AHJ's do not know what to look for, and we have pumps that need to be repaired or replaced.

OK off my soap now, enjoy your day.

YES I know I made statements and used a big brush, well so be it.....

Tom

 

[stookeyfpe]

Travis

My concern with throttling of the isolation valve is that the only way to accurately calculate the flow is to measure each discharging orifice velocity pressure and do the math. I personally find it to be a pain in my rear. I would rather control the flow through the individual hose valves. My irritation is probably a result of old age and crankyness.

Insp LC I am amazed FDNY does not require annual fire pump tests. Is it ignorance or arrogance for not requiring the tests?

 

[LCREP]

Stookey,

They are thinking of adopting NFPA 25 in 08, still a big maybe. They also do not require weekly running of a pump, testing of any kind for sprinkler systems. It is another world in NYC. We have a lot of fun trying to get clients to test and run fire pumps when the FD code does not require the testing. Then again NY Building Dept follows a code they wrote from the 1980's. If and when they ever adopt NFPA 25, sprinkler contractors will have more work then they know what to do with!

 

[TravisMack]

Stookey:

Ok..each time I have seen the test done they way I described, each hose monster had it's own pitot tube and the pitot pressure was recorded for the flow point. So, it seems like that could be an acceptable means of testing. I was concerned that we may have been doing something wrong.

I hope all is well with you lately!

T

 

[TravisMack]

LCREP:

You may have painted with broad strokes with those comments, but unfortunately, they are pretty accurate based on what I have seen in my experience as well.

T

 

[FFP1]

Obviously, I am not the only one who has developed a strong opinion regarding this matter.........hopefully some of the many valid comments on this thread will positively influence a few people in our industry. I sincerely hope everyone realizes my primary intent was to shed some light on the issue in an attempt to improve the situation.

I am very impressed with this forum and I value the information which can be obtained from the experienced individuals who participate.

 

[1954KC]

I have recently been advised to approve a Fire Water Pump system that includes a Pressure Control Valve in the discharge line.

I have been told that this Pressure Control Valve serves the purpose of maintaining a constant maximum pressure by discharging water pressure over a set limit back into the storage tank.

I should also point out that the pump maufacturer has included a Pressure Relief Valve to protect the Fire Water pump seals in the event of a closed head discharge.

Can anyone advise me if this is standard practice to install a pressure control valve as part of the normal operation in a Fire Water discharge line and if so is it recognized by NFPA?

 

[LCREP]

KC,

What size relief valve in inches are you planning to install? Diesel or electric pump driver? What is the churn pressure with the pump running, if not known, then what is the incoming water pressure to the pump and what is the fire pump rating? Answer these questions and we can help you.

NFPA has requirements based on the type of driver, type of pump and operating pressure. The relief valve can be just a casing relief valve of 3/4" or a relief valve of 4-8" depending on system pressure component ratings and pump pressures. Kind of hard to answer your questions with the limited amount of info you provided.

Tom

 

[1954KC]

Tom

Thank you for the prompt reply.

There are 2 units one electric and the other diesel. The Electric has a casing RV of 3/4 inch, the diesel does not.

The rating is 120 psi 450USGPM.

The shut off pressure is 130 psi

If necessary we can fit a PRV off each pump discharge line before the check valve.

 

[firepe]

I have to agree with TravisMack on this one. I do not see the issue with throttling the flow via the test header isolation valve. I have done this for years, with accurate results. This is in fact the way it was taught by both FM and IRI in my old days. And you're right stookeyfpe, I prolly would have been ticked at you for walking away.

I do also agree with the more improtant point raised here, which is the need for qualified personnel. I work for a union contractor, and while the union boys receive training, and would love to thump their chests and claim they know everything, that's not the case. We end up conducting in house training with our service crew, and hand select only a few individuals for pump tests. Any problems in the field are called to my direct attention immediately, and settled before they leave the site. It's a pain, but no other way to maintain quality assurance.

 

[LCREP]

KC

Are these booster pumps off a city water supply or fire pumps off a suction tank?

The diesel does not need a casing relief valve if it has a heat exchanger to keep the engine cool, the water is taken off the discharge side of the pump, thus keeping the pump cool. If it has a radiator to keep the engine cool then u will need a casing relief valve to keep the pump cool.

The diesel may need a relief valve depending on what edition of NFPA 20 is enforced by the local AHJ (I request it be put in regardless with a diesel). NFPA 20 committee has required the relief valve and then taken it out a few times in the last several revisions of NFPA 20. If it has one set it at 175 psi.

The electric pump does not need a relief valve as long it does not produce more then 175 psi in churn. If you add the shut off pressure to the city psi it should not exceed 175 psi. NFPA 20 really does not like the use of a relief valve for the sole purpose of getting the pressure below 175 psi to flatten the pump curve. The committee goes so far to say it is poor engineering practice to use the relief valve.

I hope this helps, if not, ask more questions, and I will try to help ya.

Tom