Fike looks at whether it is possible to both detect and suppress concealed fires

Everyone knows that the goal of any fire protection system is to identify a fire as early as possible so subsequent building evacuation and fire suppression systems may be activated to reliably protect people and property.

But what happens if the fire is obscured from the view of a flame detector? Or if smoke detectors are ineffective in a particularly spacious environment? How can a fire inside a small, enclosed space be detected and suppressed before evolving into a serious situation?

Fike’s Missing Piece

Since 1973 Fike Corporation has protected the world’s industries with innovative fire detection solutions, including fire panels, air sampling devices and flame detectors, and suppressed fires with chemical agent, water mist, inert gas and CO2 systems.

Missing from its product catalogue, however, was a reliable method for protecting enclosed spaces, where a small flame may quickly become a well-developed fire before being identified. Because an increasing number of users have begun adopting solutions that protect individual at-risk areas rather than an entire room with a total flood system, the Fike team quickly got to work.

The Fike Small Space Suppression System launched in 2022 and is ideal for both detecting and extinguishing fires within electrical cabinets, CNC machines, wind turbines and more.

This technology uses a flexible heat-reactive tube that is strategically routed throughout these smaller applications. Upon ignition, the tubing melts and activates the connected cylinder of 3M Novec 1230 Fire Protection Fluid to suppress the hidden fire quickly and reliably, likely before anyone even realises a fire has occurred, and most importantly, before it has a chance to spread. Finally, it does all this without electrical power.

Direct and Indirect Systems

Fike Small Space Suppression is available in two different configurations for specific applications. The direct system is engineered for electrical cabinets, which may experience a fire due to excessive heating from overloaded circuits, faulty wiring and other sources. When a fire occurs and melts the nearby segment of the nitrogen-pressurised tube, the pressure loss opens the cylinder and releases Novec 1230 from the hole in the tube and directly onto the fire.

Wind turbines are another application where the direct configuration is commonly used. A wind turbine’s fire hazards occur within the nacelle, the housing which includes the generator, brake assembly, gearbox, drivetrain and more. Mechanical failure such as misaligned bearings may create overheated surfaces or sparks and lead to difficult-to-reach fires. Traditional fire protection systems may be ineffective due to high airflow and high-voltage electrical systems within these environments, so the direct Fike Small Space Suppression System may be used as an effective alternative.

The indirect system is designed for CNC machines, which are at risk of fire due to the flammable coolant used to increase longevity and improve the performance of the system. A single spark created during production may ignite the coolant, resulting in a very dangerous situation due to the excessive amount of heat and flammable components within the machine.

The indirect system also uses pressurised tubing, but in this configuration the extinguishing agent is delivered through a network of flexible hoses leading to strategically placed, UL-listed nozzles within the hazard. Indirect systems are designed to achieve 95 percent of the minimum design concentration for flame extinguishment in 10 seconds or less.

Component Features and Specs

The Tubing: The proprietary material and unique manufacturing process allow the detection tube to offer high resistance to stress, corrosion and moisture absorption while maintaining its performance and longevity. During its manufacturing process, the tubing is constantly monitored to ensure consistent wall thickness, whereas thin tube lining could result in weak spots prone to leaking.

The Cylinders: Fike Small Space Suppression is available in 1, 2, 3, 4, 5, 6, 9, 14 and 18kg cylinders to ensure the most cost-effective size is selected for the unique application. A ball valve is integrated into a stainless steel body to reliably deliver agent into the tubing network and prevent leaks. The system is run at 360 psi to ensure the atomisation of the agent.

The Nozzles: Used in the indirect system, the nozzles are machined from brass and specifically designed to give the best dispersion of the extinguishing agent to suit the flow characteristics of the medium. The nozzles utilise an orifice plate to control the flow rate of the agent into the protected volume, and its 360-degree discharge pattern evenly distributes the agent throughout the hazard, ensuring no space is left without proper concentration. The 1, 2, 3 and 4kg cylinders use one nozzle, the 6 and 9 kg cylinders use two nozzles, and the 14 and 18kg cylinders use three nozzles.

The Agent: Novec 1230 is a fluorinated ketone stored as a liquid and discharged as a gas. It is electrically non-conductive, leaves no residue after discharge, and has a zero-ozone depletion potential (ODP), a global warming potential (GWP) of just one, and an atmospheric lifetime (ALT) of only five days. Novec 1230 extinguishes fire by removing heat from the fire. When discharged, the fluid creates a gaseous mixture with air. A higher heat capacity means that this gas mixture will absorb more heat for each degree of temperature change it experiences. 

This article was originally published in the April edition of IFSJ. To read your FREE digital copy, click here.