Page 12 - Occupational Health & Safety, October 2019

CHEMICAL SAFETY TRAINING
Chemical Process Safety and Fire Protection
The importance of implementing loss prevention and mitigation techniques that are specifically written for the chemical processing industry.
BY RON MELUCCI, JAN PERSECHINO AND TYLER FAZEWSKI
Implementing loss prevention and mitigation techniques that are specifically written for the chemical processing industry (CPI) is essential to decreasing the likelihood of releases and limiting
the resulting damage. The primary fire prevention and protection objectives in this industry are:
1. Decrease the likelihood of release.
2. Limit the amount of material that an become involved.
3. Prevent failures of vessels, piping, structural steel and safety systems that could lead to more severe events or a catastrophic loss.
In any chemical process the fundamental prin- ciples of process safety should be applied to decrease the likelihood of a release. Similarly, the fundamen- tal principles of fire protection should be applied for mitigation of consequences. It is important that these two key elements are administered and reviewed by experts in process safety and fire protection to ensure adequate protection schemes are employed.
Focusing on guidance from OSHA, EPA, and other relevant industry practices will decrease the likelihood of releases and catastrophic loss. Fire pro- tection practices are outlined in the National Fire Protection Association (NFPA) Fire Code NFPA 1 and the International Fire Code (IFC). These meth- odologies work in tandem to achieve loss prevention and mitigation.
The applicable codes require Process Hazard Analyses (PHAs) and Fire Hazard Analyses (FHAs) for most new chemical plants and those undergoing changes. The codes state that the analyses are to be performed by someone with expertise in chemical process safety and fire protection.
Additional building and system safeguards are of- ten implemented as a result of these structured and systematic analyses. This can include improved exo- thermic reactor vessel cooling systems, isolation valve installation, pipe rack protection, etc. FM Global Datasheet 7-14, Fire Protection for Chemical Plants, in- dicates that over 60 percent of the surveyed chemical plant losses between 2003 and 2014 were attributed to equipment design problems and operator error. These items are evaluated when the correct hazard analysis methodology is employed. A PHA will include an evaluation of adequate system safeguards and human reliability aspects. This type of comprehensive review should decrease the chance of having a loss due to a design or human element issue.
Chemical plants require more specialized fire protection features and systems than most industrial facilities. The extreme hazards associated with the chemical processing industry (CPI) can quickly lead to a cascading sequence of events that can result in a catastrophic loss. An unwanted release of flammable liquid, if not properly controlled, can result in a fire that can overtax sprinkler systems within several minutes. Such uncontrolled fires can compromise the integrity of vessels, piping, process safety sys- tems, or structural steel elements. This can lead to a collapse of process equipment/structures and a loss of process control.
A sprinkler system may control a chemical plant fire by cooling and wetting surrounding areas but may not extinguish fires involving flammable gases, lique- fied flammable gases, and low flash point flammable liquids. Additional consideration may therefore be needed for special fire protection systems that shield critical equipment from fire damage, particularly where loss of equipment/components can result in catastrophic losses as described above.
The fire protection systems should be designed in conjunction with, or in consideration of, the PHA. The PHA will include identification of critical equipment that is needed to prevent catastrophic loss and will esti- mate the likelihood and severity of unwanted releases.
Fire protection system design for chemical plants
12 Occupational Health & Safety | OCTOBER 2019
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