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Fire Sprinkler Systems – Understanding How and Why They Fail

November 15, 2023

Sprinkler systems are silent protectors against the threat of fires in buildings and spaces. These systems aren’t just devices; they’re guardians and have a story to tell through their pipes and sprinkler heads. In this article, we’ll take you on a journey to understand the basics of these essential safety mechanisms, breaking down their different types, parts, and the challenges they face. We’ll also be exploring materials from sturdy steel to modern CPVC, explaining why they matter and what to keep in mind during their setup and care. Real-life stories will help us understand things like accidents caused by occupants and the importance of proper setup.

We’ll also stress the importance of regular check-ups, sticking to safety rules, and keeping detailed records—essential knowledge for claims adjusters dealing with sprinkler system problems. Let’s dive into it:

When discussing sprinkler systems, the initial consideration that comes to mind, and what we should discuss, is their effectiveness. In reality, they are highly reliable and efficient at mitigating property damage when correctly installed and functioning within a building. Moreover, installing sprinkler systems can significantly reduce civilian casualties resulting from fires, with a potential decrease of up to 90%.

Our involvement comes into play when circumstances deviate from the planned course. This can occur due to improper manufacturing, design, installation, usage, or maintenance. In such cases, we are called upon to conduct inspections and offer insights into the reasons behind these deviations.

An essential aspect of sprinkler systems is their stringent regulation. Numerous standards, including NFPA 13, which addresses the installation of these systems, and NFPA 25, which focuses on inspection, testing, and maintenance, play a crucial role. These standards serve as the framework to ensure the proper execution of both installation and maintenance. When conducting investigations, adherence to these standards is paramount. This is especially true when investigating failures that stem from maintenance issues.

It’s crucial to highlight that standards are a fundamental part of the equation whenever a claim is submitted for assessment. We must consistently refer to these standards during investigations, particularly when a failure appears to be linked to maintenance. Rest assured that when offering our opinion on your claim, we will provide feedback on whether the system adhered to the standards or deviated from compliance. This ensures a comprehensive evaluation and an appropriate approach to your claim or segregation file.

Types of Sprinkler Systems

There are various types of sprinkler systems, but let’s start by covering some fundamental principles. It’s crucial to ensure we’re all on the same page. First, let’s discuss the two main types: wet and dry pipe systems.

Wet Sprinkler Systems

Wet sprinkler systems are commonly found in office spaces, warehouses, and apartment units.
Conversely, dry systems are typically installed in exposed areas like parking garages, outdoor patios, and balconies, especially in regions experiencing cold climates where exposure to freezing temperatures is a concern.

A wet pipe system operates with its entire system filled with water. It’s more straightforward and less complex than dry systems, making it less expensive to install and maintain. Around 90% of sprinkler installations use wet pipe systems due to their simplicity, reliability, and effectiveness.

Dry Pipe Systems

On the other hand, dry pipe systems have air, with water held off by a valve until needed. They’re used in areas where freezing is a concern, as the air prevents water in the pipes from freezing. However, they are more expensive to install and maintain due to their complexity. They also have a slightly slower response time compared to wet systems. When a fire is detected, the sprinkler head bursts, releasing air pressure and allowing water to extinguish the fire.

Claims related to dry systems often arise during winter when freezing occurs in pipes that were not properly drained, maintained, or inspected.

We’ve encountered two significant examples related to dry sprinkler system claims. In one instance, a constructor completed repairs on a building’s dry sprinkler system but forgot to drain one of the multiple lines, resulting in pipe bursting and a subsequent flood. In the second case, we were dealing with a retirement home where the attic required a dry sprinkler system. Due to condensation and specific construction nuances in the attic, certain areas of piping needed low-point drains. Forgetting to drain one such point led to system failure, causing substantial damage to the facility.

During our investigations, site inspections were crucial. Reviewing drawings and maintenance records allowed us to provide definitive opinions on the cause of failure. In both cases, our clients found success in their segregation efforts.

Anatomy of Sprinkler Systems

Let’s delve into the anatomy of sprinkler systems. Two key components to highlight are piping materials and sprinkler heads. While these systems are robust, we’ll cover the basics in this webinar and aim for a more detailed discussion in a subsequent session.

Piping materials mainly include steel and CPVC (chlorinated polyvinyl chloride).

Steel Pipes

Steel pipes have traditionally been favoured due to their strength, durability, and high heat resistance, ensuring water flow even in intense fires. However, they are heavy, less flexible, and susceptible to corrosion, leading to clogging and requiring maintenance checks.

CPVS Pipes

On the other hand, CPVC pipes offer flexibility and ease of installation compared to steel pipes. While they possess good characteristics, steel is more heat-resistant than they are. Corrosion and bacterial growth can lead to pipe clogging, necessitating thorough inspection during our maintenance routines.

Positives of CPVC Pipes

When it comes to CPVC pipes, the positives are very clear. It’s inexpensive, lightweight, easy to install, and corrosion-resistant. These factors provide some distinct differences between plastic and steel pipes.

For those unaware, CPVC pipes have been in use since the 1980s, offering us extensive experience with their application.
Over the years, there have been interesting changes, and currently, CPVC is becoming the most popular material of choice, largely due to its cost-effectiveness compared to steel pipe.

Negatives of CPVC Pipes

Now, let’s consider the negatives. The melting or softening point is around 100 degrees Celsius, but there’s no need for excessive concern. Even though CPVC starts to soften, it continues to function when exposed to heat, albeit with a shorter lifespan in very intense heat than steel. CPVC is susceptible to damage from UV exposure, meaning if left outside in the sun, it will degrade and incur damage. Impact or pressure, such as stepping on it, can cause cracking, which is never ideal.

In Canada, CPVC is limited to light-hazard occupancies, including low and high-rise residences, family dwellings, and manufactured homes. This contrasts with steel piping, which finds use in industrial applications.

An important point to note is that CPVC is subject to environmental stress tracking, a challenging failure mode to detect in its early stages. Unfortunately, we often discover it when it’s too late, and leaks have already begun.

Sprinkler Heads

Okay, let’s move on to the second component of interest in this topic, which is the sprinkler heads.

In most systems, each sprinkler head activates independently of the other and is triggered only when the temperature reaches a specific level. This helps minimize water damage from the discharge of that specific sprinkler head. Contrary to what some movies depict, where one activated sprinkler simultaneously sets off all of them, this is not entirely accurate. While some systems operate this way, not all activate in sync.

In any case, the important thing to keep in mind is that they work by concentrating water pressure over the area of origin. If a fire is confined to, let’s say, the kitchen area, only that specific sprinkler head will activate. Subsequent heads will activate only if the initial one cannot contain the fire, continuing until the fire is contained or suppressed by the system or the fire department.

The main parts of a sprinkler head are usually made of brass material, featuring either a heat-sensitive glass bulb or, in some cases, a soldered physical link. Once the glass bulb bursts due to temperature, water starts to flow. You often see these in residential applications or small commercial installations. Most of the time, investigating the activation of these heads without a fire or heat source can be challenging. Once that glass bulb shatters, there’s not much left for us to investigate.

There are cases when sprinkler heads can activate inadvertently or accidentally due to defects in the glass bulb or prolonged exposure to heat in the case of fusible links. However, these rare instances occur in about 1 in 16 million cases. Most of the time, head activation results from something happening—either heat or some interaction from the occupants of the building.

As mentioned, some sprinkler heads feature a fusible link instead of a glass bulb. This consists of two pieces of metal joined by a solder, released at a certain temperature. These heads are typically more robust and can be found in high-rise residential or industrial applications. They are not as susceptible to damage, and if all the pieces are found during an investigation or cleanup process, they provide a much better insight into the root cause of the failure.

Common Causes of Failures in Sprinkler Systems

Occupant Damages

One cause is occupant damages. A case study reveals an incident in a downtown hotel where a guest accidentally activated the fire alarm, causing water to spill out of a wall-mounted sprinkler head. The guest apologized, revealing they had placed a clothes hanger on one of the sprinkler heads. Such instances are common, prompting the industry to transition from exposed to concealed sprinkler heads, which are more resilient and protected from occupant damage.

More often than not, occupant damage occurs frequently in hotels with exposed heads. During investigations, it is crucial to obtain statements from all involved parties, including security personnel, witnesses, occupants, and first responders like the fire department.

Other types of damage include accidental impacts from forklifts, ladders, and sports equipment. For instance, if a baseball hits a sprinkler head in an arena, it can be damaged and go off.

In another investigation, an occupant intentionally damaged concealed sprinkler heads by placing putty or drywall compounds. This case involved all the heads in the apartment unit, raising significant concerns.

In cases where a fusible link is present, collecting all parts is vital. This allows for a close examination to determine whether heat was applied intentionally, such as with a torch or hair dryer, or if it was a manufacturing defect or material issue causing failure.

So far, we’ve covered different aspects of sprinkler systems, from their components to common causes of failures. Understanding these elements is crucial for effectively investigating and maintaining sprinkler systems.

Improper Installation

According to experts, improper installation is the second most common factor. Specifically, CPVC is obviously easier to install when dealing with plastic pipes due to its use of solvent cement instead of threaded connections. However, improperly joined sections can separate from each other, causing significant damage.

Let’s dive into a case study to illustrate this point. The joint was improperly made in a particular case, leading to separation.

As shown in the image with the red arrow, the purple-cemented pipe and the depth of insertion into the fitting were inadequate.

Additionally, the white arrow indicates poor cutting during the inspection – improper cut, deburring, and chamfering. There were several issues with the installation, compounded by high pressure nearing the upper end of specifications.

Even with a better-cut pipe, there’s a possibility that insufficient curing time for the joint or cement could lead to separation. Considering these aspects during the installation of CPVC systems is crucial. Documentation, interviews, and securing evidence are fundamental to understanding and preventing such failures.

Another issue that occurs when CPVC pipes are improperly installed is environmental stress cracking (ESC). ESC is caused by exposure to components like oils, solvents, or antimicrobial coatings in some piping. The installer must know how to prevent the pipe from coming into contact with these solvents or oils to prevent ESC. Coatings in steel pipes, electrical wiring, and other components in the building may also cause issues if they come into contact with CPVC pipes. Investigating such scenarios is vital, given that ESC originates at a molecular level and is usually undetectable until it’s too late. Severe environmental stress cracking can occur, as seen in the picture, resulting in multiple cracks in the pipe.

Moving on to sprinkler heads, when improperly installed, they may have a temperature rating inappropriate for the application. For instance, installing a sprinkler head meant for a bedroom in a commercial kitchen can lead to activation due to the accumulated heat rising to the ceiling level. We’ve encountered cases where occupancy changes led to space modifications, such as expanding a kitchen, but the sprinkler heads’ temperature rating wasn’t updated. This oversight resulted in the activation of lower-temperature-rated heads with the increased heat in the commercial kitchen.

Understanding these issues related to improper installation is crucial in preventing failures in CPVC systems and ensuring the correct functionality of sprinkler heads in various applications.

And again, whenever you observe sprinkler heads in your office or building, they have color coding. If you see orange or red, those are typically for commercial or residential applications, and the color changes as they go higher in temperature. As mentioned earlier, using the wrong head in the wrong place, especially when repurposing a space, requires recalculations and adjustments. When a space changes, such as a warehouse transforming into one with a substantial fire load, recalculating the system specifications, sprinkler head size, and system location is essential. Failure to do so can lead to system issues, as illustrated in this warehouse case with excessive carpeting. In this instance, complications arose beyond a few heads going off due to attempted fraud, where someone tried to conceal their actions behind the contractor’s work. Eventually, we proved it wasn’t the contractor’s fault but an attempt to manipulate the situation.

Maintenance is crucial for these systems; the NFPA 25 guides and controls the required maintenance. For instance, freezing in a parking garage should not occur if the pipes are correctly filled with air. Investigating such incidents can be intriguing. In the installation phase, NFPA 13 doesn’t permit the use of wet pipes unless the temperature can be consistently maintained above 4 degrees Celsius. Pushing these limits, as seen in some cases, can lead to freezing issues. It’s crucial to consider the installation and maintenance and whether appropriate heating was provided to the system.

In some cases, freezing may occur despite adequate installation and maintenance due to building heating issues. This typical failure on a steel pipe or fitting occurs when it freezes, resulting in splitting. In such cases, insulation quality matters, and an improperly insulated system can lead to freezing problems. Identifying such issues is essential for proper segregation and resolution.

Improper installation can also involve mechanical fittings needing to be tightened appropriately, leading to potential water damage. In one case, a six-inch pipe with improper installation caused significant water pressure, destroying a cinder block wall in the building’s lobby. It’s a stark reminder of the consequences of improper installation.

Turning to improper maintenance is a common issue in the field, often due to a lack of inspections or improper inspections. When you encounter such situations as an adjuster, leaving the damaged components untouched on-site is crucial. Finding someone to conduct a proper investigation is essential for documenting the system accurately. Proper documentation is vital despite the pressure to get systems back up and running.

Failures resulting from a slow leak that goes unnoticed present a more involved investigation. Determining when the leak started can be challenging but possible. It requires thorough examination and documentation to identify the root cause of the failure resulting from a slow leak.

There’s also an issue of failure to perform. If a system is rated to cover a specific area in a building, reduced flow due to blockages in the pipe, improperly functioning valves, or painted heads can result in reduced system performance. For instance, when heads are painted, it increases their activation time, reducing their effectiveness. This can lead to a fire spreading beyond what it should have if the heads had been properly maintained and inspected. Detecting such issues beforehand through regular inspections is crucial to prevent additional damages.

Corrosion is another concern in wet and dry systems, with dry systems being more susceptible due to air and residual water in the chamber. Corrosion, if not detected, inspected, and addressed, can lead to failures and resulting damages. NFPA 25 clearly identifies the required maintenance and inspection procedures to avoid such failures.

A Quick Overview of What We Discussed:

When handling a sprinkler system claim, consider the building codes and standards applicable during installation or building construction. Codes and standards may change over time, and what might seem improperly installed today could have been approved at the time of installation.

Requesting inspection and maintenance records is crucial for a thorough assessment. Documenting the scene quickly is essential, as repairs often happen immediately after an incident.

Starting the claims process early is advisable, as gathering information from third parties or the fire department can be time-consuming. Think outside the box when investigating the root cause of a failure, as the issue in one part of the system may have originated elsewhere. In complex losses, where repairs may take time, consider utilizing the opportunity to visit the site or arrange for your expert to attend.

Additionally, in such cases, discussing the possibility of a fire watch with the property manager or fire department can provide valuable time for investigation.

Manufacturer defects in sprinkler systems are rare, and each case is dealt with individually. If there’s suspicion of a manufacturing issue, it will be communicated for appropriate resolution.