If you operate a commercial kitchen, you know how important your fire suppression system is to protecting your kitchen and the people that work in it in the event of a fire. Regular inspection and maintenance as required by the 2017 Edition of the National Fire Protection Association (NFPA) 17 Standard for Dry Chemical Extinguishing Systems is critical to keep your system in good working order.
In this article, we provide a summary of the requirements in NFPA 17 for pre-engineered systems. These include the fire suppression systems that are incorporated into the types of hoods, ductwork, and cooking appliances that are found in most commercial kitchens.
NOTE: Not all jurisdictions have accepted all requirements set forth in the latest edition of NFPA 17. For specific rules and regulations required by your local authority having jurisdiction (AHJ), contact your local Koorsen Fire & Security branch to ensure you are compliant.
The Standard provides guidance on many aspects of pre-engineered systems and this article does not offer an exhaustive review of all the requirements in the Standard. Our goal at Koorsen is to provide you with the basic information you need to ensure that your fire suppression system will function properly so that you can have the confidence that your system is in compliance and will function properly when you need it.
In this article, we’ll focus on Chapter 9 of the Standard to provide an introduction to pre-engineered systems – some of the different types available and the key features they have in common, and Chapter 11, which covers the inspection and maintenance requirements of pre-engineered systems.
Chapter 9 Pre-Engineered Systems
This chapter describes four types of pre-engineered dry chemical systems common to commercial kitchens, all of which are fed with a stationary supply of dry chemical. With pre-engineered systems, the flow rates, nozzle pressures, and quantities of the extinguishing agent are already set for each nozzle based on where it is placed within the system and the size of the area the system is intended to protect. Pre-engineered systems may include:
● Local application – This is a stationary system with nozzles permanently connected to fixed piping that supplies dry chemical and aimed directly at the area they are intended to protect.
● Total flooding – This is similar to a local application system in that the nozzles are stationary and connected to fixed piping that supplies the chemical needed for fire suppression. With a total flooding system, the nozzles are arranged to surround the hazard, creating an enclosure into which the chemical is discharged.
● Hand hose lines – As the name implies, these are simply hose and nozzle assemblies connected to either fixed piping or directly to a supply and the extinguishing agent.
● A combination of local application and total flooding may also be used.
Section 9.3 is of key importance to ensuring your system functions properly at all times. This section covers the fire suppression systems specifically for your hoods, ductwork and cooking appliances, all of which must comply with the standards provided by the ANSI/UL 300, Fire Testing of Fire Extinguishing Systems for Protection of Commercial Cooking Equipment.
Key features of your system as required by the NFPA 17 include:
● The ability to function simultaneously – Each appliance and every individual hood and branch exhaust duct connected to a hood must be protected by your system. Whether your system protects each one separately or in some combination, all systems must function simultaneously in the event of a fire anywhere in the kitchen.
● Shutoff devices that automatically shut down any and all sources of heat, fuel and electric power that could feed a fire.
● A means for manual actuation – Even if your system is fully automated, you still need the ability to activate it in the event of a power outage.
● Automated systems should have monitoring devices built into them to alert you when the system is not functioning properly. They should also provide a visible or audible signal to indicate when the system has been actuated and is now in need of the inspection.
● If your fire suppression system protects an area that is also served by a fire alarm system, the two systems must be connected so that any activation of your fire suppression system will also trigger a fire alarm.
Drawings of your system installation may or may not be required by the authorities in your community. However, even if they are not required, Koorsen recommends keeping them on file because they provide a fuller understanding of your system, making it easier to perform the required inspections. A full set of drawings would include illustrations and information for all of the following:
● Appliances, hoods and exhaust ducts
● The interface between all of your fire-extinguishing system detectors
● Piping and nozzles and containers for storage of dry chemical suppressant
● Fuel shutoff devices and manual actuation devices
If you don’t have all of this information or need additional information on the types of equipment your system is intended to protect, the minimum system requirements, etc., you can probably find it in the manufacturer’s installation manual which can be found in the Underwriters Laboratory Online Certifications Directory.
11.2 Owner’s Inspection
It is important to understand that the responsibility for inspection, testing, maintenance, and recharge of your fire suppression system ultimately falls to the owner of the kitchen in which it resides. Understanding how to maintain your system in good working order is important to ensuring that it offers the protection you need.
You should be inspecting your system at least once a month in accordance with the manufacturer’s directions. However, at minimum, these inspections should include the following steps:
❏ Ensure that the extinguishing system is in its proper location and that neither the protected equipment nor the hazard has been replaced, modified, or relocated
❏ Make sure nothing is obstructing the manual actuators and that they haven’t been tampered with (this will be evident from a visual inspection of the tamper indicators)
❏ Check to see that the maintenance tag or certificate is still in place
❏ If your system has one or more pressure gauges, you’ll need to check to make sure it is within its operable range.
❏ Look at your system’s nozzle blow-off caps, too, if it has them to make sure they are intact and undamaged.
❏ You’re also going to be looking for any signs of damage to the system or maintenance issues that might impair its ability to function properly.
Monthly inspections are an important tool to ensure that your system stays in good working order. But, inspections do not eliminate the need for routine maintenance of your system. NFPA 17 requires afull inspection of your system at least twice a year (semiannually) and after any activation.
Like your monthly inspections, these inspections must follow the manufacturer’s guidelines. However, they are much more comprehensive and detailed in nature and as such, require more time and expertise than monthly inspections do. At minimum, these inspections require the following:
❏ An evaluation of your system from a hazard perspective – Has the hazard changed in any way that might make the system less effective?
❏ An examination of every component of your system – This includes your fire detectors, the containers that hold the expellant gas and extinguishing agent, your system’s releasing devices, piping, hose assemblies, nozzles, and signals as well as any auxiliary equipment.
❏ A check of the agent distribution piping throughout your system – are there any obstructions that might prevent the release and/or proper flow of extinguishing agent?
❏ An examination of the dry chemical in your system – If there is any evidence of caking, the chemical may not feed properly through your distribution system and should be discarded and the system recharged.
Regardless of the type of inspection, whether monthly or semiannual, any problems identified must be properly documented and corrected immediately to ensure the proper functioning of your system at all times.
11.5 Hydrostatic Testing
Hydrostatic testing is another important part of dry chemical extinguishing systems because many kitchens may never experience a fire sufficient to trigger the system. While this is a good thing, it means that absent a fire, the only way to verify your system will in fact function properly when you do need it is to test it. This is why, with few exceptions, the NFPA requires hydrostatic testing at least once every 12 years for the following components:
● Dry chemical containers
● Auxiliary pressure containers
● Hose assemblies
Each of these components must be subjected to a hydrostatic test pressure that is equal to that for which the system was designed. The test must be conducted for at least 30 seconds and any additional time it takes for the cylinder to become completely expanded as this is necessary to perform a proper visual inspection. During the test, the goal is to ensure that no leakage, rupture or movement of hose couplings occurs.
After testing, any dry chemical agent removed from the containers prior to testing must be discarded, and all the equipment tested should be thoroughly dried.
How Much Confidence Do You Have in Your Kitchen’s Fire Suppression System?
While it may be easy to remember the required monthly and semiannual inspections of your systems, with 12 years between hydrostatic testing and changes in personnel that can happen during that time, it can be easy to lose sight of when your next test is due. This can lead not only to compliance issues but more importantly a system that may not function properly when a fire breaks out in your kitchen.
If you have any questions about the requirements of NFPA 17 or need help with inspections and routine maintenance of your fire suppression system, contact Koorsen today. Koorsen Fire & Security offers factory-trained technicians certified in all the major fire suppression systems protecting commercial kitchens today. They can help you ensure compliance with the rules and regulations put forth by your local AHJ and give you the peace of mind in knowing that your kitchen has a safe and reliable system at all times.