In oil and gas sector fire incident can occur rapidly due to presence of flammable liquid, gases, and high pressure system and critical operations. So dealing with fire required proper understanding of fire, principles and extinguishing techniques. This article will help you to understand fire safety in better way.
Principles of Fire:
Fire is rapid chemical reaction in which oxygen combines with fuel (substance) in the presence of a source of heat. Which produce fire, this process is called Combustion.
How does a Fire Work:
There are three main components of fire. To start a fire the all three components are required. This is also called fire triangle, there are three factors to support combustion:
Fuel: This can be in form of Solid, Liquid or Gas.
Oxygen: Oxygen is present in atmosphere’s air, which is 19.5% to 23% which is good enough to start a fire.
Heat: Minimum temperature required to ignites the fire. This is also known as ignition source.
During this reaction, Heat, Flames and Smoke are produced.
Principles of Heat Transmission:
Principles of heat transmission helps in spreading fire from one place to other, three main principles of heat transmission are:
Direct Burning: Direct burning in which substance is burning itself in presence of fuel, oxygen and heat.
Convection: In this principle hot air rises and cold air sinks. Hot gases generated from the fire, rise straight up from the fire,
Inside Building: Convection help to spread the fire inside the buildings, hot gases raises insides the building and form the layer underneath the ceiling. When these hot gases touch any combustible material inside the building such as( wooden, clothes, curtains or paper), this heat is sufficient to burn those material. And in result fire build and spread heavily inside building.
Outdoor: Burning fire outside contains burning embers that are carried in the current until the air cools and the embers are dropped to the ground. This is a common way for forest fires to travel.
Conduction: This is principles in which fire heat can be transferred through solid materials, such as cooper because some metal conduct heat very efficiently. In the same way metal spoon heats ups as in a saucepan on the hob.
Radiation: Heath energy can be radiated through air in the form of infrared heat waves. Radiant heat generated by a fire shines onto nearby surface.
Causes of Fires:
Some of main causes of fire are as below:
- Electrical Equipment
- Deliberate Ignition
- Arson
- Hot work
- Smoking
- Cooking Appliances
- Heating Appliances
- Mechanical Heat
- Chemical Reactions
- Unsafe use and storage of flammable liquids and gases
Consequences:
- People Killed and injured
- Damage to buildings and property
- Environment Damage
Types of Fire According to NFPA
Class A: Wood, Paper, Cloth, Foam, Plastics.
Class B: Flammable liquids, Oil, Grease, Petrol, Diesel, Gases.
Class C: ElectricalClass D: Combustible metals, potassium, magnesium, aluminum etc.
In case of Fire: (FIRE method for Fire Safety)
- If you find the fire raise the alarm.
- By raising alarm or Inform others and emergency response team.
- Gather at assembly points restricts others to enter at the fire place.
- Make area clear for Extinguish/ Evacuate personal and fire.
Fire Extinguishing Techniques:
Understanding the correct fire extinguishing technique is critical for fire safety– not only to control the fire but also to terrible damage.
Below is primary fire extinguishing techniques uses in real-world and oil and gas operation.
Cooling (Temperature Reduction)
Cooling works by removing heat from fire, lowering the temperature below ignition point, as heath is one of fire triangle item by reducing temperature removing heat from triangle can stop fire.
Point to ponder: Cooling can be done by water so this is not suitable for hydrocarbon pool fires directly, as water can spread burning oil, can reduce fire safety
Smothering (Oxygen Removal)
Smothering can extinguish the fire by cutting off oxygen supply; Oxygen is also part of fire triangle which is essential for combustion. It works, by using foam, Carbon dioxide, or inert gas are used to create a barrier between fuel and oxygen.
Point to ponder: For fire safety this is highly effective in oil and gas industry, for CLASS B Fire (flammable liquids).
Starvation (Fuel Removal)
Starvation is removing or isolating the fuel source as fuel is very essential component of fire triangle so without it fire can no longer sustain itself. This is done by the cutting of supply of fuel by shutting of valves, isolation or stooping the flow of hydrocarbons
Chemical Inhabitation:
This is also called chain reaction interruption; this method interrupts the chemical reaction occurring in the fire. Dry Chemical Powder fire extinguisher interferes with the combustion process at molecule level.
Fire Safety Emergency Evacuation Procedure:
Every single work place have emergency plan and procedure, Fire emergency also required a specifically pre develop Emergency evacuation procedure and emergency plan emphasize on personal and fire safety, some of it key points are as follow:
- In case of fire:
- Sound the alarm
- Verbal announcement
- Leave the area and move to nearest and safest assembly points
- Who is likely to be in premises
- Action to be taken on discovering fire
- Escape routes
- Fire – Fighting equipment
- Training
Emergency procedure and emergency plan for the oil and gas industry should be develop according the OSHA and IOSH guidelines.
Point to Ponder: Good housekeeping, waste free, tidy, well ordered area play an important role in prevention of fire
Fire Safety under Safe System of work:
Fire can be prevented by following the safe system of work at work site, or any activity in which of chance of fire is high. That activity like hot work can be control by implementing the Control during the activity such as:
- Permit to work System identifying hazards and mitigation.
- Removal of combustible material and proper safe storage
- Ensuring the fire extinguisher equipment is readily available at work site and workers are trained to use for small fire.
- Monitoring after work finished and maintain good housekeeping before and after work.