Purposeful Design in Automatic Sprinkler Protection

Business Property Insurance and Fire Risk

The dangers and potential damages of fires and explosions are often the biggest threat to a business, due to the value associated with the potential damage, as well as the resulting business interruption. Property insurance transfers the risk of fires and explosions to an insurer and underscores business sustainability and continuity, but it is equally important that businesses mitigate the risk and protect lives.

A comprehensive fire protection system is the most effective way to mitigate fire and related risks. Sprinkler systems, hydrant systems, hose reels and other related systems utilising water at predetermined flows and pressures, are all designed with the purpose of containing and suppressing a fire to protect life and property.

According to Imraan Moolla, a senior risk consultant at Aon South Africa, sprinkler systems are legally required, dependent on the occupancy and size of a property. “Due to the large claims associated with fires and related incidents, these fire protection systems may also be required by insurers and reinsurers prior to them taking the risk on their books, often requiring higher levels of protection than prescribed by minimum life safety (legislative) requirements to adequately protect assets and subsequent business interruption.”

“These systems are carefully designed to cater for the specific conditions present at each protected area. The success of these systems is dependent upon the design of the system. Analysing the available water volume and supply in the form of water flow rate and pressure supplied to these systems is crucial in finding a solution that will address a fire hazard sufficiently,” he explains.

When it comes to the design of an automatic sprinkler system, it is best to follow internationally recognised standards. Legal standards, such as the SANS 10287 code in South Africa, are designed to cater for life safety which may satisfy legal requirements but is not necessarily sufficient from an insurance or asset protection perspective. Internationally recognised standards are frequently updated to stay abreast of an ever-evolving risk and occupancy profile.

Two standards that are accepted by local and international insurers and reinsurers are Factory Mutual (FM) as well as the National Fire Protection Association (NFPA). NFPA 13, The Standard for the Installation of sprinkler systems, recommends that a designer consider five key components at the design stage of a sprinkler system:

1. Water Supplies: Any water-based fire protection system is only as effective and dependable as the water supply to that system. The capacity, flow rate and pressure of water supplied to the sprinkler system must be rigorously evaluated as an integrated part of the total system design.
2. Selection of Hazard: The water required to suppress a fire involving flammable liquids versus a fire in an office building will be significantly different. It is critical that the correct hazard is selected at the design stage to ensure that the system is not under or over designed.
3. Design Approaches: There are several different approaches that are determined by the amount of water required to protect the hazard. For example, you can design the entire system to cater for the highest hazard present or design each protected area to suit a specific hazard.
4. System Components & Usage: The exact types of components utilised, which includes types of sprinkler heads, relief valves and automatic air vents, control valves and hose connections, to name a few.
5. Installation: Ensuring that the system is installed in accordance with manufacturer and listing requirements.

“There are four main types of sprinkler systems used to effectively contain and/or suppress a fire as quickly as possible. Although they share the same purpose, they are fundamentally different due to occupancy and risk variables that need to be optimised for the specific scenario in play,” Imraan explains.

The four main types of sprinkler systems include:

1. Wet Pipe: An immediate release of water upon the bursting or activation of a sprinkler head and functions on the premise of pressurised water throughout the pipe network. This is the most cost-effective system and can be used for all building occupancies – except where temperatures reach below freezing.
2. Dry Pipe: In this system there is a delay between the bursting or activation of a sprinkler head and the release of water. The pipe network is filled with compressed air or nitrogen, usually maintained via a compressor at the installation control valve. The dry valve contains a clapper, which, when the system is pressurised with air or nitrogen, remains in the closed position thus no water is able to flow to the system. Once activated, the air or nitrogen is released and the clapper opens, allowing water to fill the system and reach the required sprinkler head and is ideal where temperatures reach below freezing.
3. Pre-Action: Combines both wet and dry pipe systems and is suitable for areas that are water sensitive to protect against accidental water release from the system (such as high valued electronic equipment stores, libraries, etc.). It interfaces with a fire detection system that senses the fire, activates a pre-action valve and allows water to fill the system. From there it acts as a wet pipe system, which will release water in the event of a sprinkler head activation or burst.
4. Deluge: It consists of open sprinkler heads which all operate simultaneously in the event of a fire. The deluge valve is interfaced with a form of fire detection – this could be heat detectors, smoke detectors, flame sensors and/or fusible links. Once the fire is detected, the mechanically latched deluge valve opens or detaches which allows water to reach all sprinkler heads which then operate simultaneously.

“The type of sprinkler system is directly proportional to the effectiveness of the system in terms of either containing and/or suppressing a fire. It is imperative that consultations with approved and competent fire risk individuals are held when making such a decision,” Imraan urges.

Once the correct type of system is selected and installed, the system must be maintained as per legal, insurer and manufacturer requirements:

• Fire pumps (if applicable) need to be tested on a weekly basis. Electrically driven pumps need to run for a minimum of ten minutes to allow for a transitioned discharge of the initial electric load received when starting the pump, while diesel driven pumps should run for a minimum of thirty minutes to allow the diesel engine to achieve optimal and normal operating conditions and temperatures.
• The pumps also need to be serviced annually by approved service providers.
• Pumps must undergo an annual flow test by an independent, approved third-party.
• The system and its flow switches or alarms must be tested on a weekly basis and findings documented.
• Sprinkler system control valves need to be overhauled on a three-yearly basis.
• Installation control valves must be locked in the required positions.
• The system must be inspected in accordance with its design standard by an approved third-party at prescribed intervals. Following which, a clearance or compliance certificate must be issued by the third party and submitted to insurers.

“Too often when conducting risk engineering surveys following sprinkler analyses, clients are found to have an inadequate system in place or the maintenance controls are inadequate, which directly impacts system performance. Insurers could withhold fire cover until the issue is resolved or system is upgraded, or they could impose high deductibles and associated increased premiums,” Imraan explains.

“It is here where the input and insight of Aon’s independent risk consulting team prove invaluable in ensuring that automatic sprinkler systems - including the water supplies - are designed, inspected, serviced and maintained in accordance with recognised standards which are aligned with both regulatory and insurer requirements,” Imraan concludes.