5-Minute Guide to Commercial Property Risks - The Top-10 Reasons Why Fire Sprinkler Systems Don’t Control Fires
Intended Audience: Business Owners, Facility Managers & Safety Professionals.
The Real World Reality About Sprinkler Systems:
The most common misconception with building sprinkler systems is that they are supposed to put out a fire, as they designed to control the fire’s spread until the fire department arrives on scene.
Most newly built commercial buildings are equipped with sprinkler systems, primarily because of local building code requirements.
Office buildings are the least likely to be fully sprinklered at around 30%.
High rise buildings are the most likely fully sprinklered at about 70%.
The Effectiveness of Sprinkler Systems:
NFPA and other sources report that sprinkler systems average being 88% effective in controlling fires.
The remaining 12% failure rate can be attributed to either the system failing to operate or operating ineffectively in controlling the fire until the fire department arrives.
With the majority of building fires only 1 or 2 sprinkler heads actually activate thereby minimizing water damage.
In this article, we will focus on the main reasons behind the 12% system failures rates and what businesses owners can do to prevent them.
The Top-10 Reasons Why Fire Sprinkler Systems Don’t Control Fires (In Order of Frequency)
Corroded Sprinkler Interior Piping: The internal corrosion rate can vary with the type of piping such as steel, PVC, or copper. There are two main culprits here. First, the oxygen in the air in a dry pipe systems will eventually cause the internal surface of the pipes to rust and corrode. This is because the air compressor for the system will periodically be adding warm/moist air to the piping. The second reason is water with a high mineral content in wet pipe systems that can led to scale buildup reducing the internal pipe diameter and restricting the water flow. The best corrective action for both issues is the flushing of the complete system every 5-years to remove the rust, silt and debris. In extreme cases the sprinkler piping will need to be disassembled, cleaned or even replaced, However, this should only be done by a licensed sprinkler contractor.
Inadequate Water Supply: There are many possible causes behind this problem including inadequate water from a public water main, a break in the main water line or older, undersized water lines. One possible issue prior to 1980, was that sprinkler systems were designed using what is called the “pipe schedule method”. Modern computer models have determined that this method often inaccurately determine the amount of water needed to control a fire. As corrective action, if the cause of an inadequate water supply can’t be promptly identified, a fire protection engineer should be consulted as to what the most appropriate corrective action should be.
Sprinkler Head Obstructions: The most common problem here is that stockage or other types of impediments have been piled closer than 18-inches to the sprinkler head. Occasionally, there can be structural modifications made to a building’s interior such as the installation of walls, beams or ductwork which can negatively limit sprinkler head clearance. The issue is that these obstructions may not allow the water from the heads to fall completely down to floor level, thereby allowing the fire to expand to the point that it can’t be controlled. As a preventative measure, all sprinkler heads should be inspected annually to identify any obstructions.
Premature Sprinkler Head Activation: The main problem is that a sprinkler head starts emitting water when there is no fire. This is likely caused by some form of impact damage, corrosion or manufacturing defect. An addition problem is where the sprinkler heads are rated at too low of a temperature setting thereby causing them to activate too early with a fire. While the problem might seem trivial to the average business owner, it can result in significantly more water damage to the building, equipment and contents.
Frozen Sprinkler Piping: This is primarily a wet pipe sprinkler system problem. It can occur when the building’s inside air temperature is to low to keep the water in the sprinkler lines from freezing. When the water turns to ice, its expansion can cause the pipes to burst and the joints to break. Thus, the inside building temperature should never be allowed to drop below 40-degrees Fahrenheit. When the system cannot be maintained at the minimum interior temperature, an antifreeze solution that is specially designed for fire sprinklers should be added by a qualified sprinkler contractor.
Inadequate Sprinkler System Design: The main reason for this problem is with a building that has undergone a change in occupancy such as from light manufacturing to a warehouse with high rack storage. This can mean that there is an insufficient water density from the individual sprinkler heads to control the spread of a fire. Another reason for inadequate design is with a pipe schedule methods that was discussed previously. Regarding of the cause, the only real solution here is for a qualified sprinkler contract to correct the design deficiencies.
Closed Sprinkler Control Valves: Simply put, a closed sprinkler control valve means that the system can’t operate because of the water supply is shutoff. If the Main Control Valve is indeed open like it’s supposed to be, the lack of water could be due other reasons such as a closed Outside Stem & Yoke Valve, the Post Indicator Valve or the Butterfly Value. The most common solution here is the fitting of valve locks that are strong enough to resist even a determined tampering by a vandal. However, it maybe necessary is to see that anti-tamper devices are installed to provide the proper valve supervision.
Lack of System Upkeep: The primary culprits here are human ignorance or indifference. Another issue could be inadequate funds available for servicing by sprinkler professionals. Sprinkler control valves and gauges should be inspected monthly and this can be done by facility maintenance staff providing they have been properly trained. Main drain and trip tests should be done annually, but by a licensed sprinkler contractor. All gauges should either be calibrated or replaced every 5-years by a professional. The key determination of who conducts a sprinkler test is that any system testing, adjusting, or servicing must be conducted by a qualified fire sprinkler contractor.
Piping Blockages: Besides corrosion, sprinkler pipes can be obstructed by sand, pebbles, bacteria and debris cause by comstruction along the main water lime. This means that such obstructions can reduce the piping’s water flow rate to a level less than what is need to control a fire. As a preventative measure, an internal piping inspection should be conducted every 5-years.
Sprinkler Head Problems: These can be heads with the wrong temperature rating, those over 50-years old, dust or grease buildups and sprinkler head parts failure, to name just a few. According to NPPA Standards all sprinkler heads should be visually inspected annually. Standard sprinkler heads should be replaced every 50-years and randomly selected heads tested every 10-years, typically one for every 50-heads.
Key Takeaway Point:
A fire sprinkler system can only be effective in controlling a fire if it has been properly designed, installed, maintained and has an adequate water supply.
For Additional Information or questions on this Subject, Contact Centurion’s Loss Control Manager, Rob Brooks, at:
(606)434-0739
Disclaimer:
This publication is intended for general educational purposes only, and is not to be considered as business, financial or legal advice.
Readers should consult with appropriate professionals before making any decisions based on the content of this newsletter.
Some of the data &/or statistics referenced within were obtained using artificial intelligence.
Centurion Insurance Services and the writer make no guarantees or warranties of any kind, express or implied, about the reliability, completeness or suitability of the information contained herein.
We will not be liable for any losses or damages arising from the use of the information provided.
