Active fire protection

Relevant comparative studies and experimental investigations about the performance of such passive fire protections, as surface layers applied on FRP composites are presented in Section 9.4. 

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OTI607 Availability and properties of passive and active fire protection systems... 

A fire loss that occurs with one active fire protection system out of service, often described as the Probable Maximum Loss (PML). 

An active fire protection system requires some action to occur before it functions per its design intent. This action may be taken by either a person or control system. Examples of active fire protection systems are monitors, water spray systems, foam systems, emergency isolation valves, and ESD systems. 

Active fire protection systems can be installed to provide the desired mitigation by either manual or automatic activation. 

Automatic systems have a detection system that should automatically activate fire protection systems, significantly reducing the chance of a larger fire. The disadvantage is the potential for nuisance activations that can damage the equipment being protected, shutdown production, and require the fire protection systems to be recharged. 

This chapter provides the fundamentals of design for passive and active fire protection systems. A passive system should be used wherever possible, as this is an inherently safer approach than an active system. 

Fire barriers should be considered when the spacing recommended can not be met and hazards are not easily mitigated with active fire protection systems. Barriers, such as walls, partitions, and floors, provide physical separation of spaces and materials. The effectiveness of a fire barrier is dependant on its fire resistance, materials of construction, and the number of penetrations. Inattention to the integrity of penetrations is one of the primary reasons fire barriers fail to provide proper protection. Factors to consider in the design and placement of fire barriers include ... 

The elimination of a fire hazard may be the ideal solution, but it is often not possible. In general, the optimum level of fire protection is achieved by selecting from the other appropriate prevention and mitigation options. The higher the performance availability (or lower the probability of failure-on-demand) of each selected fire protection feature, the more effective the overall fire protection system. The generally preferred approach to improve effectiveness is to select a combination oipassive and active fire protection features. 

Flammable gas detection systems are typically used to initiate an alarm at a concentration level below the lower flammable limit (LFL). Two gas alarm levels (low and high) are often utilized to allow early warning prior to taking automatic actions. Detection systems may also be used to stop electrical power and initiate process shutdown. The low alarm setpoint should be —20% LFL and the high alarm level set point should be between 40%-60% LFL. Where these devices are used to initiate process shutdown or activate fire protection systems, it is common practice to use some form of voting, typically 2 out of 2, such that the frequency of spurious shutdowns or system activation is minimized. 

For those process vessels containing a significant quantity of flammables or heated combustibles, a combination of passive and active fire protection should be considered in addition to manual firefighting. This additional protection is usually in the form of fireproofing and fixed sprinkler or directional water spray. Additional vessel protection should be applied as follows ... 

Cable trays outside of process areas or unit battery limits are normally not provided with either passive or active fire protection regardless of size. Small cable trays are usually not fire protected regardless of location when they provide service for ancillary equipment or for equipment designed to fail to a safe state on loss of power, control signal or communication. 

Fixed active fire protection systems incorporating both water spray and foam application... 

Outdoor storage areas are seldom provided active fire protection by fixed systems to protect them from exposure by events in adjacent areas. However, on a case-by-case basis, specific fixed fire protection systems, often fire monitors, may be added where the outdoor stored material ... 

If the above indicates the need for additional fire protection, then appropriate passive and active fire protection should be applied. 

Active fire protection of cooling towers is primarily provided by sprinkler systems. 

The timing of installation of fire protection systems is important because it must be integrated with other construction activities. Fire protection is generally a small but important element of the overall project. To ensure a timely and efficient installation, the person responsible for scheduling the installation must... 

Active fire protection—A fire protection system or device that requires moving parts, detectors, instruments, electrical or other power or utilities. 

Neither cargo vessels nor tank vessels have too many requirements associated with fire safety, and the key issues covered in their chapter (Chapter 20) are construction specifications and active fire protection. However, the code also states that interior finish and furnishings in exits and exit accesses must meet the requirements of Chapter 8 and that accommodation spaces must meet the requirements of Chapter 10 (and these vessels are rarely sprinklered). 

Fusible links are made of low melting point materials designed to vent pneumatic systems as the fire melts the link. The depressurization can open fire deluge valves. Fusible links are very reliable, but they do require that the fire be well under way before they work, whereas otho- detectors, such as fire eyes, act more quickly. Depressurization of a fusible loop is considered to be a confirmed detection of a fire, and will automatically initiate appropriate shutdowns and activate fire protection equipment. 

Active fire protection systems (e.g. smoke or heat detectors, deluge sprinkler systems or foam systems). 

Translucent sandwich panels for the side-facades were also made of glass-fiber-reinforced polyester composites (see Figure 1.8). The sandwich panels consisted of two layers separated by a composite fiber sheet with trapezoidal corrugations. The surface of the facade panels was finished with fleeces that also provide resistance to aging and U V radiation. As the main function of these facade elements was thermal insulation, the sandwich panels were filled with aerogels. They were therefore able to provide a K-value of 0.4 W m with a panel thickness of only 50 mm [18]. In terms of building fire considerations, a sprinkler system was installed as an active fire protection. 

Chapters 6 and 7 demonstrated a successful implementation of an active water cooling system in FRP cellular sections for beam (or slab) and column (or wall) apphcations in building structures. Key results are summarized in Section 9.5, with a further extension of such an active fire protection system to heating and cooling usages. 

Active Fire Protection Applications with FRP Components I 225... 

An internal liquid cooling system as an active fire protection was implemented in full-scale GFRP panels for beam and column applications, the resulting thermal responses have been introduced and modeled in Chapter 6 and the mechanical responses in Chapter 7. The fire endurance time of each scenario is summarized in Table 9.1 and more details can be found in the previous chapters. It can be concluded that combined mechanical loading and fire experiments on full-scale water-cooled cellular slabs and columns proved the feasibility of an effective fire protection. Fire endurance durations of up to 2 h could be reached at slow water... 

Table 9.1 Fire endurance time of full-scale GFRP beams and columns subjected to ISO 834 fire curve with active fire protection (Internal liquid cooling).

A control system for receiving fire alarm signals and initiating actions to highlight conditions (alarms and beacons) or institute actions to automatically activate fire protective systems (i.e., fire pump startup, HVAC shutdown, etc.). The fire alarm... 

The interruption of pyrolysis by passive and/or active fire protection techniques would prevent fires to propagate beyond the ignition zone resulting in reduced fire hazards. The passive fire protection technique involves changes in the polymer to increase the values of the surface re-radiation loss and heat of gasification. 

Active fire protection is provided by appl5dng agents as liquids, gases, solid powders, or foams to the flame and/or to the surface of the burning polymers. 

Active Fire Protection Personnel Protection and Escape... 

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