Page 318 - CHEF Guide

Mitigating Safeguards and Protection Layers

20.6 Active Fire Protection includes:
 Sprinkler
o Area coverage typically application in use within buildings, labs, warehouses
 Deluge/Water Spray System (Figure 20-7)
o Structural steel protection, area protection, vessel protection
 Monitors (Figure 20-7)
o Manual, automatic, remote use
 Foam application
o Fire suppression, Vapor suppression

Figure 20-7 Images of water deluge and monitors used in fire protection

An Active Fire Protection Systems requires some means for detection of the fire. Personal observation and response
to a procedure to manually turn on a sprinkler, deluge system or fire monitor is less reliable than automated detection such
as heat sensors, smoke detectors, fusible links, or infrared devices.

 Sprinkler - fusible Link or glass bulb
 Deluge - manual, heat detection, pilot line, Intelligent Systems
 Monitors - manual, remote
 Foam application - typically automatic, could be manual

Design considerations for automatic fire suppression systems is covered by several codes and standards. Industry
consensus guidance suggests a Probability of Failure on Demand is 0.1 [78]. The evaluation team may need to review the
existing or proposed design to determine if the generic probability of failure on demand (PFD) of 0.1 is appropriate for the
specific application. If a credit has been applied to the heat input from fire for sizing of relief devices or evaluation of a pool
fire scenario, then additional credit for the fire protection system should not be taken.

20.7 Other Mitigating Safeguards or Protections include:

 Personal protective equipment
 Drainage & containment
 Excess flow valves
 Deflagration & Detonation suppression
This is a partial list as there may be many safeguards or protections that are considered mtigating or active after the
Loss Event to eliminate or reduce the severity of the consequence.

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