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Fire Engineering Technology

Fire Engineering Technology is a fire service to industrial, commercial and specialized facilities in accordance with international and local regulations. The objective is to provide management with the complete fire engineering solution for the fire safety of the facility and it's employees.

 

 

Fire Technology

Fire engineering technology is probably a term which is seldom encountered by the public. Fire safety is a general term which includes a broad spectrum of specialist functions and engineering disciplines. Fire safety is however the term that is most commonly used by the general public due to:

  • fire drills at schools and the workplace
  • fire warnings and public announcements on TV
  • fire safety signs
  • the local fire brigade
  • a fire incident ie. motor vehicle, house or bush fire

The general public encounters fire engineering technology probably everyday without realising the fact or the significance of the fact. Some examples of these are:

  • car seats, carpets and accessories that are fire retarded to limit the potential for ignition
  • furniture and carpets in the home that have a fire rating
  • dedicated fire escape routes in shopping malls, office blocks and hotels
  • ventilation systems in commercial buildings designed to deal with smoke movement
  • fire rated components ie. fire walls, fire doors, fire panels, fire dampers, etc designed to contain a fire
  • electrical apparatus that has overload features or temperature controls

Some very basic everyday interactions with fire engineering technologies have years of fire research and development incorporated and the costs of these sometimes are not recovered. What specialist or engineering functions and disciplines are typically involved. The following is a brief summary of some of these:

Every country has a fire test and research facility and incorporates a fire certification element. The fire research can be related to the burning characteristics of a solid, liquid or gas. In most instances these are now known factors due to all of the fire research that has gone on before. Large databases are now available and usually are labelled as fire safety data sheets. These are readily available on fire research institutes, universities, chemical companies and fuel supplier websites.

As material technology develops new materials are tested all year round. A new plastic piping composite may be developed using different polymers and with different fire characteristics. These characteristics may include fire resistance, flamability, ignitability, toxicity, rate of surface flame spread, structural integrity, etc. Depending where this pipe will be used some of these characteristics may be unacceptable. The manufacturer in conjunction with the client will establish what the criteria is for use. This may require changes to the manufacturing process or if this is not possible to coat or wrap the pipe in a fire retardant or fire resistant material.

Whichever option is viable will result in further fire tests to determine the minimum criteria for the specific application and a the product will be certified for a specific application. The criteria for these tests may be a time related criteria eg. retard flame spread for 60 minutes, or be fire resistant for 2 hours, maintain structural integrity for 60 minutes or must not contribute to the fire loading for the specific location. This is a specific fire criteria whereas in some instances the piping may be required to have generic fire rating for all applications.

Fire Resistance and fire retardant these terms are widely misunderstood by the public and abused by commercial suppliers. Fire resistance is the term used to define a materials ability to withstand a standard time/temperature curve fire against 3 criteria namely; insulation, integrity and combustibility.

Fire retardant is the ability of the material to retard the ignition or flame spread for a specific period at a maximum exposure temperature. Just because a material is fire retardant it is not necessarily fire resistant.

Fire Products and Manufacturers

Fire products are continuously being tested and researched. Fire extinguishers, fire equipment, fire sealants, fire engines, fire hoses, fire alarms, fire dampers, fire doors, etc. All of these products involve a high degree of engineering, technology and testing. As technology evolves new products are developed that are more efficient in combatting fire. As fire safety is the primary concern inferior fire products could result in the loss of life or assets. It is important that quality fire engineering technology is maintained in the process.

Fire Extinguishing Systems

Fire extinguishing systems include the following:

  • Water based systems
  • Foam based systems
  • Powder based systems
  • Gas based systems

These systems have evolved tremendously over the years. This is as a result of fire engineering technology evolving. The more we know how fires develop and spread the better we are able to develop fire extinguishing systems that are more reliable and efficient in dealing with fires. Some very basic concepts with water based fire extinguishing systems that has changed is the amount of water required to efficiently extinguish a fire. The less water and pressure required reduces the pump sizes, the pipe sizes, the pipe support loads, etc. which reduces the cost of the fire system. Some studies have been done to illustrate the optimum water droplet size in microns that can efficiently and quickly extinguish a fire. The challenge was therefore to develop nozzles that could deliver 90% by volume at a flow and pressure range the optimum droplet size. Nozzles were engineered, manufacturer and tested to meet the requirements.

The problem with optimising the water droplet size is that the national standards regulating water based spray systems have not been adjusted to these new flow and pressure requirements. The technology needs to be used to update the standards. Technological advances are sometimes delayed due to resistance by regulators to accept new concepts rather relying on old and trusted concepts. In some instances it is just a case of manpower to re-write these standards.

Traditional control valves on water based fire systems have changed dramatically from the old mechanical valves to valves that are more reliable, are more easily controlled by electronic, hydraulic and pneumatic controllers and provide better means for remote control and signalling. Again some of these valves are still not accepted by regulators even though they have been proven to be more efficient and adaptable.

Foam based systems have been engineered to provide better equipment to deliver the foam to the fire and the foam solutions have been developed to more efficiently spread and retain their consistency to provide better coverage. Traditionally foam was generated mechanically and many still do but a number of foams are now synthetic chemical foam solutions.

Powder based extinguishing systems have also evolved through fire engineering technology. The powders that were very generic in past years are now more specific in their design to deal with particular hazards.

Gaseous fire extinguishing systems have evolved on a number of fronts. The traditional carbon dioxide fire systems are now under threat from an environmental perspective. Various very efficient gases were introduced years ago but were found to be detrimental to the ozone layer. New gases had to be engineered to replace the halogens that were very efficient not only in the way they interacted with fire but also because they required less volume. The newer gases invariably require more volume to do the same job however fire engineering technology has changed the type of installation to a more modular system which reduces the gas volume required. Other research is taking place where the oxygen level is reduced to extinguish the fire but still at an adequate level to sustain life to facilitate evacuation of the occupants.

The above is a very brief look at some of the developments it is impossible to address all developments on fire extinguishing systems.

Fire Engineering

A bit of history regarding fire engineering and protection. Originally fire services were provided by insurance companies and/or volunteers from the community. In the case of insurance companies they maintained a fire service that only protected the paying customers. All others had to depend on the local community to assist them. These days fire services are provided by municipalities using professional, retained or volunteer fire-fighters. There are fire regulations stipulating minimum fire safety requirements administered by the local authority.

The sheer volume of new commercial facilities, industrial plants, residential complexes and public buildings that are developed and constructed on a daily basis makes it difficult to control compliance to fire regulations. It is therefore the owners or developers who are charged with insuring that fire safety is incorporated in the building construction. Fire regulations take time to evolve and to keep current with technological advances in building construction. The original concept was a 'deemed to satisfy' rule which implies that whatever the building regulations are the construction includes all the necessary and applicable building regulations as is. New building construction technologies, materials and processes invariably do not meet the criteria. The building costs are generally higher when the 'deemed to satisfy' rule is applied. Architects and engineers were limited in their choice of building materials and processes and a new concept was introduced the 'rational design'. Architects and engineers were allowed to submit a building design that met the intent of the building regulation using modern materials and processes. These 'engineered designs' were submitted to the local authorities with all the necessary supporting documentation to certify that the construction was fire safe.

As the architects and engineers generally do not have a high degree of knowledge regarding fire and fire regulations, fire specialists are approached to provide this service. The fire specialists are employed to obtain the benefit of their fire experience. Gradually it became apparent that fire experience alone did not really translate in to sound engineering advice and as these fire specialists were not certified as technologists or engineers the responsibility still rested with the building engineers and architects to certify any submissions. Fire consultants and/or fire engineers were limited as there was no academic, educational or training institutions that specialised in fire engineering or technology. Fire engineering and training academies were developed and fire specialists were required to prove by certification their knowledge of the physics of fire, fire regulations, fire protection, fire system design, fire ground experience and a sound knowledge of building construction.

Fire engineering became a specialist engineering discipline that was accepted by the general engineering fraternity as an essential component in any design and construction team. The original concept of fire protection was identifying fire risks and adding fire protection systems to deal with these risks. The modern day fire engineering concept is at the design stage of buildings and industrial plants incorporate fire safety principles in the construction materials, the industrial processes, the plant design and layout to reduce the need for add-on fire protection systems. By ensuring fire safety at the design phase a reduction in cost of maintaining and installing fire protection systems is achieved. A simple example of this process is described below.

Fire Protection Alternative 1.

A plant process requires that a flammable or combustible liquid be used. The normal solution would be to provide a fire protection system on the tanks and pumps that supply the combustible and/or flammable liquid. The cost of this would be as follows:

  • Initial cost of the fire protection system
  • A containment structure around the tanks to contain the spillage and to ensure the fire protection system covers the spillage area
  • A fire safe drainage system in the event of a spillage
  • Additional maintenance costs of the fire protection system over the life-cycle of the plant (maybe 30 - 40 years)
  • Depending on the type of system the replacement cost eg. a foam system the foam solution has a shelf life of 4 years
  • Reliability - a fire may occur at any time 'what if' the fire system does not work, the fire system is out for maintenance (Sods law), there is a minor explosion that damages the fire system, a fire system is a combination of mechanical and electronic equipment failure rates have to be considered.

Fire Protection Alternative 2.

The combustible and/or flammable liquid is located at a remote location. The benefits are as follow:

  • fire risk is less because of the separation distance from the process plant normally 15 meters
  • the reduction in ignition probabilities
  • a containment wall ensures there is no spillage exposure to other plant as required above
  • the piping is provided with safety valves to limit flow and/or leak detection using double jacketed piping
  • additional piping and valve costs (which is offset by the piping and valves for the fire system)
  • limited additional life-cycle maintenance costs

Alternative 2 is the more cost effective solution and guiding principles are as follows:

  • can the risk be eliminated
  • can the risk be reduced
  • in the case that none of the above applies then protect the risk

These decisions are made at the design phase if the plant is already under construction it is difficult to implement these fire engineering solutions. Any architect or engineer will tell you that retro-fitting or back-fitting a plant is almost double the cost and in some instances totally impractical. Fire engineering is done at the planning stage to be effective.

What is fire engineering technology

The above is a brief overview of fire engineering technology. Around the world research institutes, commercial developers, fire authorities are continuously looking at ways to reduce the impact of fires. There are new fire extinguishing systems, equipment and products being introduced on a regular basis. New fireground tactics are being introduced from 'lessons learnt' from fires around the world. Research is taking place on major fires, the fire scenario is reproduced using computer fire models to evaluate how the fire developed, spread and what the exposure levels were at different stages of the fire development. These studies are all valuable in the development of fire engineering technology.

Fire engineers need to use all of these resources to better educate themselves, to increase their knowledge base and to be aware of these developments worldwide. The internet provides an incredible advantage to the modern day fire engineer that was not available to his/her predecessors. In conclusion, fire engineering technology is the knowledge developed in all matters pertaining to fire.

 

 

 

Contact Details:

Box 860 Edenvale South Africa 1610

Mobile: +27793277985

tony.botha@fire-eng.co.za