NFPA 13 – 2025 updates under obstructions

NFPA 13 – 2025 updates for supplemental sprinklers under obstructions 

The 2025 edition of NFPA 13 introduces significant updates regarding supplemental sprinklers under obstructions, particularly clarifying their definition, requirements, and hydraulic calculations. Key changes include defining "supplemental sprinklers," specifying when they are needed, and providing guidelines for their placement, spacing, and characteristics. 

Definition and Scope:

·        The 2025 edition introduces the term "supplemental sprinklers" to refer to sprinklers installed specifically below obstructions. 

·        These sprinklers are often required under obstructions like ducts, beams, or catwalks that can impede the spray pattern of ceiling-mounted sprinklers. 

·        The definition clarifies that supplemental sprinklers are intended to address coverage gaps created by obstructions. 

Yes, obstructions in buildings can significantly hinder the effectiveness of fire sprinkler systems. These obstructions, whether they are structural elements, stored items, or even decorations, can prevent water from reaching the fire, delay sprinkler activation, or disrupt the intended spray pattern, potentially leading to increased fire damage and hazards.

Here's why obstructions are problematic: 

·        Delayed Activation:

Obstructions, especially those close to the sprinkler head (within 18 inches), can block the heat from reaching the sprinkler's heat-sensitive element, delaying its activation.

·        Disrupted Spray Pattern:

Obstructions can interfere with the sprinkler's ability to distribute water effectively, potentially creating "shadows" where the water doesn't reach, leaving areas vulnerable to fire spread.

·        Reduced Water Coverage:

When obstructions block the sprinkler's spray pattern, the area covered by the water is reduced, limiting the sprinkler's ability to suppress or extinguish the fire.

·        Structural Damage:

In some cases, obstructions, like heavy items hung from sprinkler pipes, can damage the system itself, leading to leaks or even system failure.

Key Changes and Clarifications:

Non-Flat and Non-Solid Obstructions:

The standard clarifies when supplemental sprinklers are needed for non-flat and non-solid obstructions, such as cable trays with openings. 

Shielding:

Supplemental sprinklers under non-flat, non-solid, or open grating obstructions require a shield or water shield to protect them from the heat of the fire.

Sprinkler Characteristics:

The 2025 edition allows supplemental sprinklers to differ from ceiling sprinklers in terms of K-factor, orientation, and coverage area under certain conditions.

Hydraulic Calculations:

NFPA 13-2025 clarifies when and how supplemental sprinklers need to be hydraulically calculated, especially when they are not supplied by the same piping as the ceiling sprinklers.

Spacing:

New spacing guidelines permit supplemental sprinklers to apply unobstructed building spacing, rather than requiring them to be spaced as if they were ceiling sprinklers. 

ESFR and CMSA Sprinklers:

Specific guidelines are provided for ESFR and CMSA sprinklers, which are particularly sensitive to obstructions, with closer spacing requirements for non-flat and solid obstructions.

Concrete Tee Obstructions:

The 2025 edition limits the depth of concrete tees to 30 inches and requires the deflector to be at least 1 inch below the bottom plane.

To mitigate these risks, it's crucial to:

Follow NFPA 13 Guidelines:

Adhere to the National Fire Protection Association's (NFPA) guidelines regarding sprinkler placement and spacing relative to obstructions.

Maintain Clear Space:

Ensure a clear space of at least 18 inches below the sprinkler head and maintain adequate spacing from any obstructions according to the "three times rule" (the distance from an obstruction should be at least three times the obstruction's maximum dimension, up to a maximum of 24 inches).

Communicate with Designers:

Involve fire protection system designers early in the design and construction process to optimize sprinkler coverage and account for potential obstructions.

Proper Storage Practices:

Avoid storing items too close to sprinkler heads, especially in areas like walk-in refrigerators or freezers.

Regular Inspections:

Conduct regular inspections of sprinkler systems to identify and address any potential obstructions or damage.

How sprinklers work and fire sprinkler obstruction types

To understand obstructions, we must first review how sprinklers work. Their job is to wet surfaces (especially walls and floors) in their design (coverage) area, and most do it by spraying water in a roughly umbrella-shaped pattern.

An obstruction is anything that blocks the spray from a sprinkler—disrupting the spray pattern from developing, preventing water from reaching the hazard, or both.

Types of Obstructions

Obstructed construction (3.3.139) refers to exposed structural members (beams, trusses, rafters, etc.) that block water spray or heat distribution. NFPA 13 dedicates special sections (10.2.6.1.2) to the arrangement of sprinkler heads in obstructed construction.

A noncontinuous obstruction (3.3.140) affects water spray from one sprinkler only. This could be a small object like a light fixture or smoke detector.

The above item contrasts with continuous obstructions (3.3.140.1), such as soffits, beams, or ducts, which block water spray from two or more adjacent sprinklers.

Storage is an obstruction category covered more in-depth by NFPA 25: Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems. The basic concept involves keeping boxes, pallets, or other stacked storage sufficiently far from sprinkler heads. The standard minimum clearance required is 18 inches (NFPA 25, 2023: 5.2.1.2.1), though different situations call for more room.

From the 2022 edition of NFPA 13

9.1.1* The requirements for spacing, location, and position of sprinklers shall be based on the following principles: […]

(3)* Sprinklers shall be positioned and located so as to provide satisfactory performance with respect to activation time and distribution.

9.5.5.1* Performance Objective.

Sprinklers shall be located so as to minimize obstructions to discharge as defined in 9.5.5.2 and 9.5.5.3, or additional sprinklers shall be provided to ensure adequate coverage of the hazard. (See Figure A.‍9.5.5.1.) 

So, it might be helpful for building owners and any design professionals in charge to prioritize solutions in terms of positioning obstructions instead of sprinklers. The reasoning: if an inspector regards anything as a violation, it’s easier to move something like a smoke detector (even if it’s hard-wired) than a sprinkler connected to fixed supply pipes.

A good place to start: “the three times rule”

Many fire protection pros know the “three-times rule” articulated in section 10.2.7.3.1.3 of NFPA 13 (2022 edition). The gist is that sprinklers should be spaced away from an obstruction at a distance at least three times the object’s maximum dimension (its height or width, whichever is greater)—up to 24 inches of separation, maximum. (As long as something is further than 24 inches away, the dimensions of that object don’t matter—unless it’s a big vertical column).

The three-times rule is an important measurement to consider, and here’s a diagram illustrating the concept:

However, it isn’t always necessary to use the three-times rule. NFPA 13 intends the section to handle obstructions where water is expected to be able to throw on both sides or around an object, whether that’s a column, light fixture, or smoke detector. The rule is generally focused on ensuring the sprinkler’s spray pattern development in those upper 18 inches.

In addition, there are exceptions to having to use the three-times rule: NFPA 13 states that in light and ordinary hazard occupancies, “structural members only shall be considered” when using it (10.2.7.3.1.4)—meaning a column qualifies and not a smoke detector, for example. The standard points readers dealing with light or ordinary hazard occupancies to other rules in sections 10.2.7.2 and 10.2.7.4.2. (We’ll cover both of these scenarios below: “the beam rule” and “handling bigger obstructions,” respectively)

NFPA 13 provides various scenarios for using this rule in Table 10.2.7.2(a) and Figure 10.2.7.2(a). We’ve reproduced both for you below. In short, the closer your sprinkler is to the obstruction’s side, the more level the sprinkler must be with the bottom of the object:

Distance from Sprinklers to Side of Obstruction (A) (ft)	Maximum Allowable Distance of Deflector Above Bottom of Obstruction (B) [in.]
Less than 1′	0
1′ or more	2-1⁄2″ or less
1-1⁄2′ or more	3-1⁄2″ or less
2′ or more	5-1⁄2″ or less
2-1⁄2′ or more	7-1⁄2″ or less
3′ or more	9-1⁄2″ or less
3-1⁄2′ or more	12″ or less
4′ or more	14″ or less
4-1⁄2′ or more	16-1⁄2″ or less
5′ or more	18″ or less
5-1⁄2′ or more	20″ or less
6′ or more	24″ or less
6-1⁄2′ or more	30″ or less
7′ or more	35″ or less

 

Figure 10.2.7.2(a) illustrates how to use the beam rule and Table 10.2.7.2(a). The smaller the horizontal distance between the sprinkler and the obstruction (A), the smaller the vertical distance between the sprinkler deflector and the obstruction’s bottom (B) must be. For example, referencing the above table reveals that if a sprinkler is less than one foot away from the side of the obstruction, its deflector must be completely level with the bottom of the obstacle. This allows the sprinkler to spray under it without impacting the pattern. Image source: NFPA 13.

Figure/Table 10.2.7.2(a) above applies to obstructions away from walls. And there are similar but unique rules (with a more complex formula) for obstructions against walls. They are:

1.   If the obstruction is less than 24 inches wide, there is no limit to how close a pendent or upright sprinkler can be to it, provided other rules about sprinkler spacing from walls are followed.

2.   If the obstruction is less than or equal to 30 inches wide, you can use a formula to determine how far away the sprinkler should be. This calculation is based on the size of the potential obstruction and the vertical distance between the item and the sprinkler. 

The obstructions against walls directives are illustrated in Figures 10.2.7.2b-c:

Figure 10.2.7.2(c) shows that there is no limit to how close a pendent or upright sprinkler can be to the bottom of an obstruction that is against a wall if the object is 24 inches wide or less, provided other rules about sprinkler spacing from walls are followed.

Figure 10.2.7.2(b) shows the formula for calculating the sprinkler distance from a wall obstruction as long as it is not over 30 inches (750 mm) in width. The calculation is based on the width of the object and the comparative height of the sprinkler’s deflector.

Hallways can be tricky environments, with little room to arrange sprinklers and plenty of small things like light fixtures and smoke detectors that get in the way. Per NFPA 13’s Figure 10.2.7.2(c), if:

1.   The hallway is no wider than 6 feet, and

2.   An obstruction is no bigger than 12 inches across

… a sprinkler can be placed on either side of the object, at least 12 inches away. This image helps explain it:

Things can get tight in hallways. However, they also limit the space sprinklers need to protect. So, NFPA 13 has lighter rules for small obstructions (1 foot or less across) in small hallways (6 feet or less wide). Image source: NFPA 13.

About Author:

Dr. Arindam Bhadra is a Fire safety consultant & ISO Auditor based in Kolkata, India, with over 20 years of experience in Fire safety systems. He’s currently founding director of the Sprinkler Fire Safety Awareness and Welfare Foundation & SSA Integrate. He is working on Fire Safety awareness, training, consultancy & Audit in same field. Dr. Arindam Bhadra is popularly known as "Fire ka Doctor" because of his expertise in fire safety, prevention, and awareness, helping people and organizations stay safe from fire hazards. He is Member of NFPA, Conformity Assessment Society (CAS), FSAI, Institution of Safety Engineers (India) etc. He is certified fire Inspector and certified Fire Protection professional.

NOVEC 1230 is Obsolete

Are NOVEC 1230 is Obsolete

The 3M Company (originally the Minnesota Mining and Manufacturing Company) is an American multinational conglomerate operating in the fields of industry, worker safety, and consumer goods.

The chemical dodecafluoro- 2-methyl-3-pentanone is chemical Name of a component. structural formula is CF₃CF₂C(=O)CF(CF₃)₂, which is a fully-fluorinated analog of ethyl isopropyl ketone. It removing heat from a fire, which is a safer method in occupied spaces compared to agents that remove oxygen. It is used as an electronics coolant liquid and fire protection fluid.  3M named this chemical as NOVEC 1230. ASHRAE designation: FK-5-1-12. So NOVEC 1230 is the brand name for a clean agent fire suppression fluid.

On Dec. 20, 2022 3M issued a notice to announcing its exit from all per- and polyfluoroalkyl substance (PFAS) manufacturing, which includes the discontinuation of all NOVEC fluids, including Novec 1230, by the end of 2025.

Effective January 13, 2023, 3M no longer offers the "3M Blue Sky Warranty" for new purchasers of Novec 1230 systems. Existing warranties registered before this date will still be honored for their remaining term.

✅ Chemically identical:
Both FK-5-1-12 and NOVEC 1230 share the same formula C₆F₁₂O (Dodecafluoro-2-methylpentan-3-one).
The difference lies only in branding:
 • FK-5-1-12 → Generic chemical name used in standards (NFPA 2001 & ISO 14520)
 • Novec 1230 → Trade name registered by 3M

✅ Key Features
• Safe for people (non-toxic, breathable).
• Zero ozone depletion potential (environment friendly 🌍).
• Leaves no residue, so no cleanup required.
• Fast acting → prevents fire spread.
• Compact storage → stored as liquid, discharged as gas.

⚙️ How FK-5-1-12 Works
1. Detection → Smoke/heat detectors sense fire.
2. Alarm → A pre-discharge alarm alerts occupants.
3. Discharge → FK-5-1-12 is released through nozzles.
4. Action → The gas quickly absorbs heat and interrupts the chemical reaction of fire, extinguishing it in seconds.

✅ It is also important to note here that FK-5-1-12 remains an acceptable fire suppression solution to be considered where clean agents are necessary. It is considered acceptable by the U.S. EPA via their SNAP program and is included in NFPA 2001 and ISO 14520 standards as well as other similar, global standards.

This should be a relief to anyone who is currently using a fire suppression system using Novec 1230 fluid. It’s also important to remember there are plenty of other in-kind and not-in-kind technologies available in the marketplace.

In a recent meeting, no comments were submitted to the NFPA Gaseous Fire Extinguishing (GFE) Committee governing NFPA 2001 that would affect FK-5-1-12 in terms of its supply or restrictions in any way. It is still considered acceptable in NFPA 2001 and in the U.S. EPA SNAP Program, the same as other commercial clean agents, just as it was in the Federal Register in 2002 when it was first commercialized as NOVEC 1230 fluid.

✅ ISO 14520 establishes minimum requirements for gaseous fire-extinguishing systems, covering the design, installation, and safety of clean agents. The standard is divided into multiple parts, with ISO 14520-1 providing the general framework for total flooding systems, and other parts specifying requirements for individual extinguishants like HFCs and FK-5-1-12. It is essential to use ISO 14520 in conjunction with its specific parts for the agent being used.

✅Key aspects of ISO 14520

Scope: 

It applies to total flooding systems using electrically non-conducting clean agents that leave no residue after discharge, which are suitable for use in buildings, plants, and other structures. It does not cover CO2 or explosion suppression.

✅ System Design: 

The standard provides guidance on designing systems, including specifying the correct quantity and distribution of the fire suppression agent for effective fire extinguishment.

·        Extinguishant Properties: 

ISO 14520 outlines the physical properties and characteristics of gaseous agents, which are critical for system design and understanding how they work.

·        Safety and Performance: 

The standard includes requirements for the performance and safety of the systems, ensuring they are reliable and safe for use by people and equipment.

·        Specific Parts: 

The standard is a series of documents, with different parts dedicated to specific extinguishants. For example:

·        ISO 14520-5: Covers FK-5-1-12.

·        ISO 14520-10: Covers HFC 23.

·        ISO 14520-8: Provides information on environmental properties of extinguishants like HFC 125.

·        Compliance: 

It is essential to use the relevant part of ISO 14520 for the specific extinguishant being used in the system.

✅ Design Process

1. Define the Hazard

2. Determine Design Concentration

3. Determine the Net Hazard Volume

4. Determine Extinguishing agent Quantity

5. Check the maximum reach concentration

6. Determine number and size of agent containers

7. Establish maximum Discharge time

8. Determine nozzle size and quantity to deliver required concentration at required discharge time to ensure mixing

9. Determine pipe sizes and pipe run (Pipe Sizing & Flow Calculation)

10. Evaluate compartment over/underpressurization and provide venting if required.

11. Establish minimum agent hold requirements and evaluate compartments for leakage.

✅ Parts of an FK-5-1-12 System

The following components will usually form part of an FM-200™ System and should be included in the checks:

·        Signage

·        Bottle Cage/Bottle Rack and Bracketry

·        Pilot Gas Bottle/s [optional]

·        Main Gas Bottle/s

·        Clean Agent Gas

·        Pressure Gauge

·        Pressure Relief Valve

·        Pilot Line

·        Check Valves

·        Hangers and Supports

·        Discharge Header/Manifold

·        Distribution Pipework

·        Pipework Fittings and Connections

·        Discharge Nozzles

·        Control Panel

·        Battery

·        Battery Charger

·        Control Valve/Solenoid

·        Local Door Panel

·        Emergency Release Button

·        Key Switch

·        Sounder/Bells

·        Beacon/Strobe

·        Smoke/Heat Detectors

·        Ventilation Damper System Interlocks

·        Ventilation and Air Conditioning Equipment Tripping System

📌 Applications
✓ Data centers 💻
✓ Control rooms ⚡
✓ Telecom facilities 📡
✓ Archives & museums 📚🎨
✓ Industrial automation areas 🏭

✅ Safety Precautions and Maintenance

A FK-5-1-12 system maintenance checklist includes monthly, semi-annual, and annual tasks such as checking for physical damage, verifying nozzle caps are in place, inspecting agent container pressure and weight, and testing the control panel and alarm system. A full system evaluation, including a room integrity test, should be performed annually, while professional, comprehensive services are required periodically, often every five to ten years. 

✅ Ensure FK-5-1-12  cylinders are installed as per NFPA 2001 standards.

✅ Conduct periodic inspections for cylinder pressure, valves, and piping.

✅ Train employees on evacuation procedures in case the system activates.

✅ Keep access areas clear for quick maintenance and refills.

✅ Never tamper with detection or discharge systems.

 

✅ Who will complete the maintenance?

If the building construction process is still ongoing or it is still within the defect’s liability period, then the responsibility for the maintenance will be the general/main contractor/system integrator.

Where the building/systems are outside of the defects liability period, the maintenance of the unit will be completed by the building facilities manager/operator.

They will either have their in-house team complete the works or will sublet to a facilities maintenance/building services contractor. Contractor must be have necessary technical knowledge (validate based on professional certification or Engagement with fire safety industry related various association) and experience (validate based on appreciation letter from there customers) specific to clean agent fire suppression systems. All works will be completed by an experienced, knowledgeable, and trained engineer who has previous relevant experience completing this type of work.

CFPS or WBITM certified freelancer or individual will get 1^st preference.

✅ Daily Inspection Checklist

Ensure the inspection is completed in line with all specific health and safety requirements of the site/building and all permits are in place:

Ref	Type	Inspection/Task	Notes
D-1	Inspect	Taking onboard any temperature differences, check each cylinder pressure gauge to ensure proper operating pressures are shown.	If the gauges show a loss of more than 5% at the cylinder valve then the bottle will need to be refilled in line with manufacturers requirements.

✅ Monthly Inspection Checklist

Ensure the inspection is completed in line with all specific health and safety requirements of the site/building and all permits are in place:

Ref	Type	Inspection/Task	Notes
M-1	Review	Review the protected space to ensure the hazard or usage has not been changed or modified.	If any changes, raise this with the building owner immediately.
M-2	Review	All previous observations have been rectified and closed.
M-3	Inspect	Inspect the complete system to note any damage or missing parts.	Where any damage is noted, remedial action must be completed immediately.
M-4	Inspect	Inspect the pipework for any rust or corrosion.	Where rust and/or corrosion is noted treatment, cleaning and repainting should be completed immediately.
M-5	Inspect	Inspect system discharge nozzles to ensure are not obstructed, clogged, dirty, painted, etc.	Where obstructed/clogged, remedial action must be completed immediately. If noted are dirty, ensure they are clean.
M-6	Inspect	Inspect system beacons, strobes, sounders detectors to ensure are not obstructed, dirty, painted, etc.	Where obstructed, remedial action should be completed. If noted are dirty, ensure they are clean.
M-7	Inspect	Inspect mechanical fans and dampers to ensure are not obstructed.	Where obstructed, remedial action should be completed.
M-8	Inspect	Access to the area is unobstructed.	Where obstructed remedial action must be completed immediately.
M-9	Inspect	Access to cylinders is unobstructed.	Where obstructed remedial action must be completed immediately.
M-10	Inspect	Ensure system discharge nozzles are not restricted or obstructed.	Where obstructed remedial action must be completed immediately.
M-11	Inspect	Access to control/releasing panel is unobstructed.	Where obstructed remedial action must be completed immediately.
M-12	Inspect	Inspect the control/releasing panel has power and no alarms on the system.	Any issues should be investigated and corrected immediately. Any alarms should be cleared or investigated and assessed to understand if there are any fundamental problems.
M-13	Inspect	Where any batteries are installed to provide a resilient electrical supply, inspect that the charge is in line with the design.
M-14	Inspect	Access to manual emergency switches is unobstructed.	Where obstructed remedial action must be completed immediately.
M-15	Inspect	Inspect emergency switches/pull stations for damage.	Where any damage is noted, remedial action must be completed immediately in line with manufacturers requirements.
M-16	Inspect	Inspect pressure switches for damage	Where any damage is noted, remedial action must be completed immediately in line with manufacturers requirements.
M-17	Inspect	Inspect all discharge hoses for any fraying, damage, loose connections, cracks, and cuts.	Tighten any connections and replace hoses that are damaged, with an equally rated hose.
M-18	Inspect	Inspect any actuation lines for damage, loose fittings, cracks, or cuts and cleanliness	Tighten any connections and replace lines that are damaged, with equally rated equipment.
M-19	Inspect	Inspect all fittings and adaptors to bottles to ensure are not damaged or loose.	Tighten any connections and replace anything that is damaged.
M-20	Inspect	Inspect all pilot tube connections to ensure are not damaged or loose.	Tighten any connections and replace anything that is damaged.
M-21	Inspect	Inspect all FM-200 bottle pressure operated control heads for damage, corrosion, cracks, cleanliness, and if loose.	Tighten any heads that are loose, clean in line with manufacturers’ advice, and replace anything that is damaged.
M-22	Inspect	Inspect all FM-200 bottle electronic control operated heads for damage, corrosion, cracks, cleanliness, and if loose. Also, ensure to check all electrical connections to ensure are tight.	Tighten any heads that are loose, clean in line with manufacturers’ advice, and replace anything that is damaged.
M-23	Inspect	Inspect Cylinder and its valve assembly for damage, corrosion, cracks, cleanliness, and general wear and tear.	Replace any damaged parts in line with manufacturers requirements.
M-24	Inspect	Inspect Cylinder burst disc and pressure gauges and its valve assembly for damage, corrosion, cracks, cleanliness, and general wear and tear.	Replace any damaged parts in line with manufacturers requirements.
M-25	Inspect	Inspect all brackets and straps/ mounting equipment that are securing the bottles in place.	Replace/tighten any that are loose or damaged in line with the manufacturers requirements.
M-26	Weigh	Using a calibrated scale, weigh all FM200 Cylinders and compare results with expectations, to ensure the quantity of gas is correct, and attach the result to the FM200 cylinder for proof.	Where measured weight is 95% of the original charge weight, replace the cylinder in line with the manufacturers requirements.

🟩 6-Month Inspection Checklist

Ensure the inspection is completed in line with all specific health and safety requirements of the site/building and that all permits are in place:

Ref	Type	Inspection/Task	Notes
6-1	Weigh	Weigh: Using a calibrated scale, weigh all FM200 Cylinders and compare results with expectations, to ensure the quantity of gas is correct, and attach the result to the FM200 cylinder for proof. The following information should be documented on a tag and attached to the bottle: Date of inspection Person performing inspection Type of gas The gross weight of the bottle and net weight of agent [halocarbon clean agents only] Container pressure and temperature.	Where measured weight shows a loss of 5% of the original charge weight, replace the cylinder in line with the manufacturers requirements. [see later sections for an overview of how to weigh the bottles]
6-2	Verify	Inspect: Use a calibrated device to prove the FM200 bottle pressure gauges are displaying the correct information.	Where any issues are noted, gauges should be replaced in line with the manufacturer’s requirements.
6-3	Test	Test: all pressure switches for operation.	Any issues remedial actions should be completed immediately. [see later sections for an overview of how to test]
6-4	Inspect	Test: Electric control head.	Any issues remedial actions should be completed immediately. [see later sections for an overview of how to test]
6-5	Inspect	Inspect: the enclosure of the space (walls, floors, ceilings) to understand if there are any changes to its integrity such as new holes or failed fire stopping, etc.	Any issues should be rectified, and a room integrity test conducted.

🟩 12-Month Inspection Checklist

Ensure the inspection is completed in line with all specific health and safety requirements of the site/building and that all permits are in place:

Ref	Type	Inspection/Task	Notes
Y-1	Test	Test complete full testing of the system, discharge test not required, including all ventilation integrations to prove operating in line with the design.
Y-2	Inspect	Inspect the enclosure of the space (walls, floors, ceilings) to understand if there are any changes to its integrity such as new holes or failed fire stopping, etc.	Any issues should be rectified sealing all holes in line with the fire rating of the wall/floor, and room integrity test conducted.
Y-3	Document	Documentation – Ensure all documentation is up to date and stored/filed correctly.

🟩 24-Months Inspection Checklist

Ensure the inspection is completed in line with all specific health and safety requirements of the site/building and that all permits are in place:

Ref	Type	Inspection/Task	Notes
2-1	Test	Blow through Pipework to clear it of any dust and debris that has accumulated over time.	In line with the manufacturer's instructions. [see later sections for an overview of how to weigh the bottles]

🟩 60-Month Inspection Checklist

Ensure the inspection is completed in line with all specific health and safety requirements of the site/building and that all permits are in place:

Ref	Type	Inspection/Task	Notes
5-1	Test	Bottle Test Bottles that have not been discharged and in continuous service should have a complete visual inspection in line with the Compressed Gas Association Pamphlet C-6.	In line with the noted pamphlet. Where damage or corrosion is noted, the cylinder should be emptied, tested, and restamped. If the bottles have been discharged a full test and restamping should be conducted in line with the Department of Transport Code of Federal Regulations (CFR) Title 49, Section 173.34.

🟨 Single Cylinder System [Removal]

Step	Inspection/Task
Step 1	Disconnect the electrical connection at the supervisory pressure switch (if installed), then remove the wire lead protection or conduit. Install the protective cap on the switch connection port after unscrewing the switch from the cylinder valve.
Step 2	Remove the control head from the FM-200 cylinder by disconnecting the swivel nut on the control head from the cylinder valve actuation port.
Step 3	Cover the actuation port of the FM200 cylinder valve with a protective cover.
Step 4	Loosen the swivel nut and remove the flexible discharge hose from the outlet port adapter.
Step 5	Install the safety cap on the cylinder valve outlet port.
Step 6	Undo the FM200 bottle cylinder strap/bracket.
Step 7	Remove the cylinder.
Step 8	Place the cylinder on a scale and measure weight.
Step 9	From the plate information [metal stamp] on the cylinder subtract the gross weight of the cylinder from the tare weight [empty] to understand the net weight of the original gas charge.
Step 10	Weigh the cylinder then subtract the tare weight from the scale weight to understand the net weight of the agent in the cylinder. If the net weight is less than 95% of the original gas charge the cylinder should be replaced.
Step 11	Record the following: Bottle reference Date Cylinder tare [empty] weight [from bottle information] Gross cylinder weight [from bottle information] Scale weight Net gas charge weight
Step 12	Attach the information to the cylinder.

🟨 Single Cylinder System [Reinstatement]

Once weighing has been completed, the bottle should be reinstalled in the system.

Step	Inspection/Task
Step 1	Remove the cylinder/bottle from the scale.
Step 2	Place the cylinder back into the fixing/bracket system with the valve outlet towards the cylinder discharge piping.
Step 3	Tighten the strap/bracket to hold the bottle in place.
Step 4	Remove the safety cap from the head and outlet port.
Step 5	Reconnect the flexible discharge hose to the outlet port.
Step 6	Remove the protective cover from the actuation port of the cylinder valve
Step 7	Install the control head. Ensure the actuating pin is fully retracted before attaching to the cylinder so that there is no risk of accidental discharge.
Step 8	Reinstall the electrical supervisory pressure switch.

🟨 Multiple Cylinder System [Removal]

Step	Inspection/Task
Step 1	Disconnect the electrical connection at the supervisory pressure switches (if installed), then remove the wire lead protection or conduit from all bottles Install the protective cap on the switch connection port after unscrewing the switch from the cylinder valve.
Step 2	Remove the control head from each FM-200 cylinder by disconnecting the swivel nut on the control head from the cylinder valve actuation port. Leave the flexible actuation hoses to the pressure operated control heads.
Step 3	Cover all actuation ports of the FM200 cylinder valves with a protective cover.
Step 4	Remove the tubing from the master cylinder adapter on the master cylinder.
Step 5	Install the safety cap on the master cylinder adapter port.
Step 6	Remove the flexible discharge hose from the outlet port by loosening the swivel nut. Ensure that there is a safety cap installed at the cylinder valve outlet.
Step 7	Undo the FM200 bottle cylinder strap/bracket.
Step 8	Remove the cylinder.
Step 9	Place the cylinder on a scale and measure weight.
Step 10	From the plate information [metal stamp] on the cylinder subtract the gross weight of the cylinder from the tare weight [empty] to understand the net weight of the original gas charge.
Step 11	Weigh the cylinder then subtract the tare weight from the scale weight to understand the net weight of the agent in the cylinder. If the net weight is less than 95% of the original gas charge the cylinder should be replaced.
Step 12	Record the following: Bottle reference Date Cylinder tare [empty] weight [from bottle information] Gross cylinder weight [from bottle information] Scale weight Net gas charge weight
Step 13	Attach the information to the cylinder.

🟨 Multiple Cylinder System [Reinstatement]

Once weighing has been completed, the bottles should be reinstalled in the system.

Step	Inspection/Task
Step 1	Remove the cylinder/bottle from the scale.
Step 2	Place the cylinder back into the fixing/bracket system with the valve outlet towards the cylinder discharge piping.
Step 3	Tighten the strap/bracket to hold the bottle in place.
Step 4	Remove the safety cap from the head and outlet ports.
Step 5	Reconnect the flexible discharge hose to the outlet ports.
Step 6	Remove the protective cover from the master cylinder adaptor port then reconnect to the slave bottle ports on the master cylinder.
Step 7	Remove the protective caps from all other FM-200 cylinder valve ports.
Step 8	Install the control heads. Ensure the actuating pin is fully retracted before attaching to the cylinder so that there is no risk of accidental discharge.
Step 9	Reinstall the electrical supervisory pressure switches.

🟧 Pressure Switch Test Example

The following is a simple overview of how a pressure switch test could be tested, depending upon the system design and components.

Step	Inspection/Task
Step 1	Ensure the relevant permit to work and health and safety paperwork is in place and works are authorized.
Step 2	The full system is fully operational
Step 3	Operate the pressure switch manually by pulling up on the plunger
Step 4	Verify that all systems are integrated with the FM200 system shut-down, ventilation, access control etc.
Step 5	Reset pressure switch and systems.

🟧 Electric Control Head Test

The following is a simple overview of how an electric control head could be tested, dependent upon the system design and components.

Step	Inspection/Task
Step 1	Ensure the relevant permit to work and health and safety paperwork is in place and works are authorized.
Step 2	Ensure all electric control heads are disconnected from the FM200 cylinders & nitrogen pilot cylinders serving the area, to remove risk of any accidental discharge.
Step 3	The full system is fully operational
Step 4	Activate the system via pushing the manual emergency activation button.
Step 5	Verify that the system has operated, the electrical control head will switch to its released position via the movement of pin. Any heads that have not activated, check their electrical continuity. Replace any damaged, non-operating heads and repeat the test to ensure total system is working.
Step 6	Manually reset the control heads to ensure will not create an accidental discharge when being re-connected to the bottles, then connect back onto their applicable cylinder.
Step 7	Check system is automatic and ready to operate if needed.

✅ Additional Tips to Make Your FK-5-1-12 System Last Longer

These proven practices help extend system life and improve reliability. Following these guidelines reduces maintenance costs while maximizing protection.

·        Temperature Control: Maintain consistent room temperature between 65-75°F (18-24°C). Temperature fluctuations can affect system pressure and sensor operation.

·        Humidity Management: Keep relative humidity below 65% to prevent corrosion and electrical problems. Install dehumidifiers if needed to maintain proper conditions.

·        Access Control: Restrict access to protected areas to authorized personnel only. Unauthorized modifications or activities can compromise system effectiveness.

·        Documentation: Maintain detailed records of all maintenance activities and system changes. Good documentation helps identify trends and simplifies troubleshooting.

·        Staff Training: Train facility staff on basic system operation and emergency procedures. Knowledgeable staff can respond appropriately to system warnings and emergencies.

✅ Common FK-5-1-12   System Maintenance Mistakes to Avoid

Learning from others’ mistakes helps prevent costly problems with your system. Watch out for these common maintenance oversights.

·        Skipping Documentation: Failing to record maintenance activities and test results makes it difficult to track system health over time. Keep detailed logs of all inspections and tests.

·        Ignoring Minor Issues: Small problems often develop into major failures if left unaddressed. Investigate and correct all system warnings promptly.

·        Delaying Professional Service: Attempting complex maintenance without proper certification risks system damage and warranty violations. Always use certified technicians for technical work.

·        Neglecting Room Integrity: Changes to room construction or ventilation can compromise suppression effectiveness. Evaluate all facility modifications for impact on system performance.

·        Insufficient Staff Training: Untrained personnel may inadvertently damage system components or respond incorrectly to alarms. Maintain a regular training program for all relevant staff.

✅ References

·        NFPA (2022). Standard on Clean Agent Fire Extinguishing Systems, NFPA 2001. National Fire Protection Association, USA.

·        3M (2021). NOVEC 1230 Fire Protection Fluid Technical Data Sheet.

·        OSHA (2020). Fire Safety in Industrial and Data Center Environments. Occupational Safety and Health Administration, USA.

About Author:

Dr. Arindam Bhadra is a Fire safety consultant  & ISO Auditor based in Kolkata, India, with over 20 years of experience in Fire safety systems. He’s currently founding director of the Sprinkler Fire Safety Awareness and Welfare Foundation & SSA Integrate. He working on Fire Safety awareness, training, consultancy & Audit in same field. Dr. Arindam Bhadra is popularly known as "Fire ka Doctor" because of his expertise in fire safety, prevention, and awareness, helping people and organizations stay safe from fire hazards. He is Member of NFPA, Conformity Assessment Society (CAS), FSAI, Institution of Safety Engineers (India) etc. He is certified fire Inspector and certified Fire Protection professional.