The Constantly Evolving NFPA 25

No one can doubt the importance of having a properly functioning fire pump ready to operate when there is a fire. But stationary fire pumps and their controllers spend the majority of their life not running at all – just sitting there. If there is a problem with your automobile, chances are you will see this as it operates – not when it’s parked on the street. So how to you ensure that equipment that is a) not running, b) located in a part of the building that is scarcely attended, and c) equipment that is rarely on anyone’s mind — but at the same time so crucial to life and property – is in proper working order and will operated as intended? You test and operate it on a regular basis! NFPA 25 helps guide you along the way.

If you are unfamiliar with the NFPA 25, it is the standard that governs the inspection, testing, and maintenance of water-based fire protection systems. Put forth in 1992, the NFPA 25 has evolved over the years, and covers evaluation techniques like fire sprinkler inspections, fire pump flow tests, and more. It is estimated that the effective use of the NFPA 25 can reduce the risk of death by 80%, as well as the average property loss by almost 70%. But lately this standard has come under question as to its adequacy in ensuring successful operation of these water-based fire protection systems.

There are several issues with the NFPA 25 that many have started to express their concerns with, and a symposium is even being hosted this December in Chicago to discuss these issues ahead of the 2017 revision cycle. Some of the most pressing questions being asked are:

Why do design issues, like areas not reached by a sprinkler, or spray pattern obstructions go unreported even after inspection by qualified personnel? Is it the inspectors job to notify the owner since this is supposed to be covered in the initial system setup through the NFPA 13?
What happens if owners delegate responsibility to outside contractors in ensuring the proper inspection, testing, and maintenance of their water-based fire protection systems, and the contractor only partially fulfills these responsibilities? This can occur because the agreed upon contract states that owners are responsible for the rest of the duties not covered, without fully realizing what is needed.
What happens if inspectors don’t inquire about the adequacy of the system? Some of the forms contractors use pose this question, but most do not.
Say the building has undergone changes, such as renovations. How can the owner be expected to have the knowledge about water-based fire protection systems in order to honor the responsibility of making sure these changes don’t affect the performance of the sprinkler system?
Do monthly inspections of valves need to examine more than just one possibility for a sprinkler failure?
How much of the inspection, testing, and maintenance of water-based fire protection systems can reasonably be expected of owners, and do they fully understand what is required?

As you can see, there are a surprisingly large number of important questions with regard to the effectiveness of the NFPA 25. This list only scratches the service of questions and topics that will likely be covered at the NFPA’s symposium in December. If you’d like to learn more, be sure to check out the NFPA’s website, or keep an eye on our blog page here for a follow-up in the future. Later articles will be presented here which focus on the specifics of NFPA 25 and how it covers the proper maintenance and testing of fire pumps, controllers, motors and engines, and how to best ensure that your equipment is ready to run when needed.

Do I Need a Main Relief Valve on Diesel Fire Pumps?

One of the more common misconceptions we see when it comes to diesel fire pumps is that you are no longer required to have a main relief valve, also incorrectly referred to as a relief valve in some cases, for your fire pump installation. In order to comply with the National Fire Protection Association’s code 20, or NFPA 20, you need to determine two different things first. These are:

The expected performance of the specific diesel fire pump being considered
The expected maximum static suction pressure feeding the fire pump

Once you have these, you can quickly determine whether or not you’ll need a main relief valve for your diesel pump. Simply take the fire pump’s churn pressure and multiply that number by 1.21, and add the result to the maximum suction pressure you expect for the pump. If your answer exceeds the pressure rating of your discharge fittings (and it would not have if you hadn’t multiplied by 1.21), then you *do* require a main relief valve. For those curious as to where the 1.21 comes from; The pressure from a centrifugal impeller is a square of its speed. It is expected that a listed diesel-driven engine will engage an “overspeed shutdown” condition once the rated speed is exceeded by ten percent, so mathematically we have 1.10 x 1.10 = 1.21. See Figure A for an example.

The fire pump churn pressure can be found in published curves from the manufacturer. They are not all the same! Even after performing the above math, you can easily get different results depending on the fire pump churn pressure.

Don’t just assume churn pressure. Take a look at the individual performance curves. We sell an Aurora pump model with a 100-101% churn pressure, which is a tremendous help to estimators who know of its existence. We also keep a library of every certified performance curve from every fire pump we have sold so we can research and find an even higher accuracy of expected churn performance from our equipment, and go one step beyond the published catalog curves.

The intent of fire pump main relief valves is that they be used as a safety device, to be activated in the event of an engine overspeed situation. They should not be operating under normal operation as a means to regulate system pressure, as was once common practice in the industry. Refer to NFPA 20 (2013) 4.7.7.2

As safety is a primary concern for us at Steven Brown Associates, we recommend going beyond just complying with the NFPA 20. Because engine overspeed safety devices frequently operate at 120% of rated speed rather than 110%, we recommend using the pump’s churn pressure multiplied by 1.44, instead of 1.21. Consult with your local Authority Having Jurisdiction for their opinion on the matter.

If you’d like to learn more, or have additional questions, feel free to reply to this post, call us at the contact number below, or use our service or info request page.

Pentair Nijhuis Merges with Fairbanks Morse

Earlier this year Pentair Nijhuis and Fairbanks Morse announced a merger to bring together two of the leading brands in the fire protection market. In response to this news, we have begun carrying the Fairbanks Nijhuis line of products! If you are looking for anything from compact fire pump systems to vertical turbine fire pumps and anything in between, Steven Brown & Associates can fill this need for you.

The Fairbanks Morse brand name (also a Pentair brand), has been an industry leader in fire protection for over 75 years, and many of their fire pumps are still in service today. So if you need replacement parts, rotating elements, or even a completely new pump, you have come to the right place. In future blogs, we will review the important data needed from your existing Fairbanks Morse fire pump to ensure that you get the correct, factory-authorized parts.

We have recently updated our website, and created a whole new page for our Fairbanks Nijhuis line of fire protection equipment. Be sure to check out our Fairbanks Nijhuis product page on our website to learn more.

As we told you in our last blog, keep an eye out here for more exciting news to come. If you have any questions, comments, or concerns be sure to leave us a comment, or give us a call at the number listed on our contact us page.