The Fire Rescue Department In Malaysia Engineering Essay

In Malaysia, Fire Rescue Department or popularly known as Bomba is the fire and rescue services agency. The fire safety standards must be implemented by following the regulations in the Uniform Building By-Law (UBBL) 1984, National Fire Protection Association (NFPA) Codes and Standards and Fire Services Act 1988.

2.1.1 Uniform Building By-Law (UBBL) 1984

Uniform Building By-Law (UBBL) 1984 is a published document, which is used as a required safety standard and also is emphasized by the government. The Standing Committee recommended that life safety of the building occupants must be considered first and it is to be achieved by giving the minimum requirement regarding to the various aspects. The various aspects refer to egress for the occupants, spread of fire within the building or from one building to another one building and means of detection and extinguishing of fires.

In UBBL 1984, 80 percent emphasized on life safety requirement and 20 percent are remaining on the property protection of a building (Goh, 2009). Besides, the basic requirements of the UBBL are adequate fire protection materials and construction system to make sure the safety of the life and property in the building during the fire. Furthermore, UBBL 1984 also stated some fire requirements regarding the construction design in order to minimize and decrease the risk of fire.

Automatic fire sprinkler system is mentioned in Uniform Building By-Law 1984 at Part VIII (Fire Alarm, Fire Detection, Fire Extinguishment and Fire Fighting Access).

2.1.2 National Fire Protection Association (NFPA)

National Fire Protection Association is an international non-profit organization which is authorized on fire, electrical and building safety. The NFPA was established in 1896 and it serves as the world’s leading advocate in fire prevention and is an authoritative source for information on fire safety (Tharmarajan, 2007). Besides that, NFPA develops, publishes, and disseminates about 300 consensus codes and standards which intended to minimize the effects of fire and other risk. Actually for every building, process, service, design, and installation in society today is already affected by NFPA documents (National Fire Protection Association, 2009).

Automatic fire sprinkler is mentioned in NFPA 13 (Standard for the Installation of Sprinkler Systems), NFPA 25 (Standard for the Inspection, Testing, Maintenance of Water-Based Fire Protection System)

2.1.3 Fire Services Act 1988

The Fire Services Act 1988 is implemented to make necessary provision for the effective and efficient functioning of the fire Services Department. In addition, this act is also for the protection of person and property from fire risks and other purposes connected therewith. This Act most likely explains the duties of the Fire service Department, which consists of implementing fire prevention, fire safety inspection and fire hazard abatement, investigation and prosecution (Tharmarajan, 2007).

2.2 Types of fire sprinkler systems

Fire sprinkler systems are the most important and successful of the fire fighting systems. There are five main types of fire sprinkler system which are wet pipe, dry pipe, pre-action, re-cycling and alternate wet and dry pipe. The three additional types of fire sprinkler system which are tail-end alternate, tail-end dry pipe and deluge. These three systems may be combined with wet pipe and/or alternate wet and dry pipe sprinkler system to form extensions. The type of sprinkler systems to be selected for the building will be depended on type of building and type of materials to be protected (Hassan, 1996). For example, a storage facility that stores highly flammable liquids will need a different sprinkler system from a shopping centre.

2.2.1 Wet pipe system

Wet pipe systems are the most common fire sprinkler system that have been using in the building. This sprinkler system is suitable used in heated buildings where temperatures remain above 0 and there is no risk of the water in the sprinkler system freezing (Hassan, 1996). Water is constantly maintained within the distribution piping. When a fire produced the heat, it will cause the nearest sprinkler heads to open at their operating temperature. Water will immediately discharged onto the fire, at the same time the flow of water activates a hydraulically operated alarm bell outside the building and arrangements can also be made to alert the local Fire Brigade (Hassan, 1996). Figure 2.1 shows a typical wet sprinkler system where the water supply is taken directly from the water main. Figure 2.2 shows how the pipe connected the alarm valve to an alarm gong and turbine.

The total number of sprinklers that connected to an installation will be different for light hazard, ordinary hazard and high hazard and, depending on the circumstances. Besides that, the number of sprinklers system fitted to each installation will vary over the range of 500 to 1000 (Hassan, 1996).

When fire sprinkler systems installed in a high rise building, the difference in height between the lowest and the highest sprinkler in an installation must not be greater than 45 meters (Hassan, 1996). Distribution pipes are to be connected independently to the main rise pipe at the floor being served and no section shall extend to more than one floor, mean that each section being served by a separate main rise pipe.

Figure 2.1 Figure 2.2

2.2.1.1 Advantages of wet pipe sprinkler system

Simplicity and reliability system

Wet pipe sprinkler systems have the fewest number of components and require less installation time compare to other systems. Due to the system’s simplicity, the system maintenance may not be performed as the desired frequency. The reliability of wet pipe sprinkler system is important since sprinklers may be used to standby for many years before they are needed (API Group, 2003).

Financial saving

The installation and maintenance expense for wet pipe sprinkler system are relative low (API Group, 2003). It is because wet pipe sprinkler systems require least amount of installation time and also less service time is required.

Ease of modification

The works to modify the wet pipe sprinkler system include shutting down the water supply, draining pipes and making alterations. After then, the following work is to pressure test the system and restore it. Additional work for detection and special control equipment is avoidable which may saves the time and cost (API Group, 2003).

Shorter time to repair after fire

Wet pipe sprinkler systems require the least amount of effort and time to restore after a fire (API Group, 2003). In most instances, fire sprinkler is reinstated by replacing the fused sprinklers and turning the water supply back on. For other types of sprinkler systems, it may require additional effort to reset control equipment.

2.2.1.2 Disadvantages of wet pipe sprinkler system

The disadvantages of wet pipe sprinkler system are that it cannot be installed in an area where distribution pipes are exposed to freezing temperatures. It is because the water inside the distribution pipe will become solid if exposed to freezing temperatures.

2.2.2 Dry pipe system

This system may only be used in the conditions that it is impossible to use a wet pipe system, or alternate wet and dry type system. Dry pipe sprinkler systems are installed in areas where distribution pipes are exposed to freezing temperatures. For example, dry pipe sprinkler systems will be installed at unheated buildings and parking garages.

The system between dry pipe system and wet pipe system are different. The difference is that, wet pipe sprinkler systems contain water but dry pipe sprinkler systems contain compressed air. The compressed air is supplied by an electric air compressor, nitrogen bottles, or other source. In addition, the air pressure inside the pipes that is about one-third to one-half times greater than the maximum water pressure.

Dry pipe sprinkler systems have a valve clapper and alarm port. The function of dry pipe valve clapper is to separate between air pressure and water pressure at the valve interface. When a fire starts, fire release the heat causes a sprinkler head to open and the compressed air would be released. Once this happened, water will enter the pipe and flowing through open sprinkler onto the fire.

Due to this system is liable to suffer frost damage, it is important that the pipe work should be self-draining and sprinkler heads must be fitted above the range pipes. The number of sprinkler fitted to each installation shall be within the range 125 to 500, and depends on whether or not an accelerator has been fitted to the system (Hassan, 1996). Figure 2.3 shows how sprinkler heads fitted above the range pipe.

2.2.2.1 Advantages of dry pipe sprinkler system

Suitable for freezing temperatures

Dry pipe sprinkler systems are suitable to be installed in areas where distribution pipes are exposed to freezing temperatures. For example, dry pipe installations include unheated buildings and parking garages.

Suitable for water sensitive areas

The advantage of dry pipe sprinkler systems is that it is suitable to be used to protect collections and other water sensitive areas while the wet pipe system does not. While a physical damage on the wet pipe sprinkler systems will cause the pipes leaking, dry pipe sprinkler system will not. It will take 1 minute to release the air inside the pipes before water flowing.

2.2.2.2 Disadvantages of dry pipe sprinkler system

Increased complexity

According to API Group, dry pipe sprinkler systems require additional control equipment and air pressure supply components which will increase complexity of the systems. If proper maintenance is not followed for this sprinkler system, the system would be less reliable.

Higher installation and maintenance cost

The installation cost for dry pipe sprinkler system will be higher since the complexity level is higher and installation time is longer compare to wet pipe system. Besides that, the maintenance cost will also be higher due to labour skill is required to maintain this complex sprinkler systems.

Lower design flexibility

There are strict requirements regarding the maximum permitted size of individual dry pipe systems (API Group, 2003). These limitations may impact the ability of an owner to make system additions.

Increased fire response time

The total time taken from sprinkler head opens until water is discharged onto the fire is up to 60 seconds (API Group, 2003). The fire extinguishing actions will be delay for 60 seconds and caused the fire damage to the building increase.

Increased corrosion potential

Dry pipe sprinkler systems must be completely drained and dried. If there is water remaining inside the pipe, it will cause corrosion and premature failure. This kind of problem will not happen on wet pipe system because the water is constantly maintained in piping.

2.2.3 Pre-action system

Pre-action sprinkler systems are installed in water sensitive environments such as computer rooms, library and paper records office. When in an actual fire condition, these systems will operate to save the building and its components from fire damage. It will give earliest warning if detected of combustion in the protected areas and which will arise from the action of a smoke detector. This will gives enough time for the outbreak to be dealt with satisfactorily by using portable extinguishers.

The pre-action system is similar to a dry pipe system and deluge system. The difference between pre-action system and dry pipe system is that the air pressure may or may not be used for pre-action system. The difference between pre-action system and deluge system is that the valve is electronically held closed and standard “closed” are used for pre-action system.

Two separate events must be presented to initiate sprinkler discharge onto the fire. Firstly, the detection system identifies a developing fire and then automatically sprinkler system would open the pre-action valve. When the pre-action valve is opened, it allows water to flow into system piping. Secondly, each of the sprinkler heads will verify whether there is fire then only permit water flow onto the fire.

This system must be self-draining. For pre-action sprinkler system installation, the maximum numbers of sprinklers that may be fitted to an installation for light hazard is about 500, ordinary hazard and high hazard is about 1000 (Hassan, 1996).

2.2.3.1 Advantages of pre-action sprinkler system

The dual action required water release

The dual action here means that the pre-action valve must operate and sprinkler head must fuse then only water release (API Group, 2003). This feature provides double level of protection against inadvertent discharge. With this reason, pre-action sprinkler systems are frequently installed in water sensitive areas such as book libraries, computer centers and etc.

2.2.3.2 Disadvantages of pre-action sprinkler system

Higher installation and maintenance cost

Pre-action sprinkler systems are more complex with several additional components, such as fire detection system. Thus the installation and maintenance cost will become higher due to the additions system required.

Modification difficulties

Pre-action sprinkler systems have specific size limitations which may affect future system modifications (API Group, 2003). Besides that, system modifications must incorporate changes to the fire detection and control system to ensure proper operation.

Potential decreased reliability

The higher level of complexity with pre-action sprinkler systems the higher possibility that something may not work when needed. Regular maintenance is needed to ensure reliability.

2.2.4 Alternate wet and dry pipe system

This system is used for those developments in which the water in the pipes may freeze when change in the climate and where the surrounding temperature does not exceed 70. For example, the system is operated ‘dry’ in winter and ‘wet’ in the summer.

The system inside the pipes will be changes by following the climate, when it is dry pipe system then the pipes contain compressed air, and when it is changes to wet pipe system then the pipes are filled with water.

In some cases, this system may require a duplication of the automatic alarm valves, which may be connected in parallel. The benefit of the automatic alarm valves is to facilities an easy changeover at the turn of the season. Besides that, the system must be self-draining and the number of sprinkler fitted to each installation shall be within the range 125 to 500 (Hassan, 1996).

2.2.5 Recycling system

The use of this system is generally restricted to situation where it is necessary:

To limit water damage after a conflagration;

To prevent inadvertent water damage caused by any accident mechanical interference with the pipe work or sprinklers; and

To be able to carry out work on the installation while ensuring that the system remains in a state of readiness at all times.

When pre-action valve turn to open mean than the operation of any heat detector activates the alarm driven gong and primes the pipe work ready for the imminent opening of one or more sprinklers. If the fire was put out by portable extinguishers immediately, the heat detectors automatically reset to the normal monitoring position. This has the effect of initiating a hydraulic pressure equalization process which may typically take 5 minutes to complete. After this has occurred, the pre-action valve will be from opened and turn to closed. If the fire begins to rekindle, the heat detectors will be reactivated and cause the pre-action valve again be opened. After then water will be directed discharge to the source of the fire.

Others installations use electrical timing units and the use of electrically interlocking circuitry is installed to ensure that the system will not operate solely because of falling air pressure in the pipe work. With this system, any accidental damage to either the pipe work, or the sprinkler heads will not cause the main valve to open. The disadvantage is when operatives working on such an installation must take care that they isolate that part of the system on which they are working from the potentially active main system. The system must be self-draining and the number of sprinklers fitted to such an installation must not exceed 1000 (Hassan, 1996).

2.2.6 Deluge system

Deluge sprinkler systems are installed in high hazard operations, such as power generating station, chemical storage, munitions plants, and the areas which store items such as flammable liquids. These sprinkler systems will work together with independent fire detection systems and discharge water immediately to the protected area during a fire. The deluge sprinkler system is similar to a pre-action system. The difference between deluge sprinkler system and pre-action system is that the deluge sprinkler heads are open and the pipe is not pressurized with air.

Deluge systems are connected to a water supply through a deluge valve that is opened when smoke or heat detection system is activated. The detection system is installed in the same area as the sprinklers. When the detection system is activated, water will discharges through all of the sprinkler heads onto the fire. Water is not adequate to control or extinguishment fire in areas where flammable liquids are manufactured or stored. Water is require to mixed with the foam concentrate and cause the concentrate to expand when released through the sprinkler head, it may depriving the fire source of oxygen required to support combustion of flammable materials (Hassan, 1996).

2.2.7 Tail-end alternate pipe and tail-end dry pipe systems

These systems may be regarded as an ‘add-on’ system to a standard sprinkler installation and they are intended to deal with comparatively small areas.

In a heated buildings will served by a conventional wet pipe system, it is possible that a small part of the building is either unheated or is overheated temperatures. In order to deal with this, it is permissible to join a tail-end alternate system onto the main wet pipe system.

The number of sprinklers on any tail-end extension must not exceed 100. If it is more than two tail-end extensions are services by one valve set, the total number of sprinklers in the tail-end extension must not exceed 250 (Hassan, 1996).

2.3 Benefit of fire sprinkler system

Automatic fire sprinkler systems have been used to protect industrial and commercial properties for more than 100 years. Nowadays, fire sprinklers are not only installed in commercial and industrial buildings but also installed in residential buildings, office buildings, schools and hotels. Fire sprinkler systems are become common and popular that is because it is provide many benefits to us.

2.3.1 Reduce fatalities

It is difficult to estimate how much safer fire sprinklers could provide in the event of fire. Based on evidence from laboratory studies and limited field experience in the United States, the studies prove that fire sprinklers could save an additional 7.7 lives per million houses per year. In addition, the evidence also proves that fire sprinklers could reduce the risk of firefighter death and injury during put out a fire. It is estimated if all the buildings were installed with fire sprinklers, about 0.1 firefighter lives could be saved per million houses per year. Thus, the study concludes that fire sprinkler could save an additional 7.8 lives per million houses per year (Rousseau, 1989).

2.3.2 Reduce injuries

Based on the United Stated research, the study proves that if installation of fire sprinkler in buildings could prevent about 87 people injuries per million houses each year. The amount of firefighting injuries could also be reduced through increased installation of sprinklers by as many as 30 firefighting injuries per million houses per year. Based on American Studies, the cost to remedial per injury to a civilian or firefighter is $30,000 (Rousseau, 1989). These costs are included to pay medical bills and allowance for pain and suffering.

2.3.3 Reduce Insurance Premiums

Residential fire sprinkler systems are becoming more prevalent with each passing year. If the building installed with fire sprinkler systems, it will cause the additional 1 to 2 % increase in the final cost of the house (Snyder, 2008). Besides that, municipalities must account for the increase in residential system and ensure that they are being maintained in accordance with current National Fire Protection Association standards.

After installed fire sprinkler systems, they will actually save money because they can reduce home insurance rates by 5 to 15 percent (Snyder, 2008). These values are expected to be increase in the future. In the event that there is a fire, they will also save money in potential damages.

2.3.4 Increase value of the building

A building constructed with fire sprinkler system has more value than a building without a fire sprinkler system. It is because a building with a fire sprinkler system provides additional fire safety for the building and thus, the building worth more and the owner could gain more profit when selling the building.

2.3.5 Reduce property damage cost

According to records for decades on property damage, the owner save about 90% on property damage costs with fire sprinkler systems than those without fire sprinkler systems when a fire is happened. This is clear that a fire sprinkler system will pay for itself many times over. According to Daniel Snyder article, the average cost of damages in homes with fire sprinkler systems was about $2,000 and the average cost of damages in homes without sprinkler systems was about $45,000.

2.3.6 More time to escape

Fire sprinkler systems provide an additional degree of protection for both life and property above smoke and other fire detection systems. Sprinkler systems obviously help people by giving more time for them to escape when a fire is happening, so they help to save lives. A correctly designed and installed sprinkler system can detect and control a fire at an early stage of fire development and activate an alarm. So with the correct operation of the sprinkler system will rapidly reduce the production rate of heat and smoke, thus allowing more time for the occupants to escape safety or be rescued.

2.3.7 Increase exit access travel distance capacity

An increase in exit access travel distances is a major distinct advantage for buildings with sprinkler system over buildings without sprinkler system. The exit access travel distance mean the distance from any occupied portion of a building to an exit. For example, the exit is such as enclosed stairway. Depending on the occupancy of the building, anywhere from an additional 50 to 100 feet of exit access travel distance can be gained when the building is installed with fire sprinkler system (International Building Codes, 2006). Table 2.1 show the maximum travel distance between building with sprinkler and without sprinkler for different types of buildings.

SEVENTH SCHEDULE

MAXIMUM TRAVEL DISTANCES

(By-law 165 (4), 166 (2), 167 (1), 170 (b))

Purpose Group

Limit when alternative exits are available

(2) (3)

Dead-End limit (metre)

Un-

sprinklered

Sprinklered

Small Residential

Institutional

Hospitals, Nursing Homes etc,

School

Open Plan

Flexible Plan

Other Residential

Hotels

Flats

Dormitories

Office

Shops

Factory

General and Special Purpose

High Hazard

Open structure

Places of Assembly

Storage and General

Low an Ordinary hazard

High Hazard

Parking Garages

Aircraft Hangars (Ground Floor)

Aircraft hangars (Mezzanine Floor)

22.5

Table 2.1 (Sources from Uniform Building By-Law 1984)

2.3.8 Increase Egress capacity

For the occupancies buildings which are installed with fire sprinkler systems, except high-hazard and hospital, the means of egress components can be increased 50% for the staircase width and 33% for all other egress components such as corridors, doors, ramps (International Building Codes, 2006).

For example, a 44 inch of exit staircase construct in a building which is without fire sprinkler systems only can serve 146 persons, but a same 44 inch of exit staircase construct in a building which is installed with fire sprinkler system can serve 220 persons. Besides that, 44 inch corridor construct with fire sprinkler system can serve 293 persons, without fire sprinkler system can serve 220 persons.

2.3.9 Reduce construction cost

As previously mention, if the new building installed with fire sprinkler systems, it will cause the additional 1 to 2 % increase in the final cost of the house. They are not only can cut low the insurance premiums but also reduce in construction cost. This is because most building codes provide large construction leeway for sprinkler buildings. For example, fewer egresses are required and larger floor areas are allowed for the building with sprinkler systems installed. This feasible design will help owners and occupants to cut down the construction cost and material cost. Further more information about the advantages of fire sprinkler system relate to benefits of construction cost saving will be explain as below:

2.3.9.1 Reduction in shaft enclosures

For building are not greater than 420 feet in height, the fire rating of vertical shaft such as HVAC, electrical, plumbing, trash/linen chutes, except exit enclosures and elevator hoist way enclosures, is permitted to be reduced to one hour where automatic sprinklers are installed within the shaft at the top and at alternate floor levels (International Building Codes, 2006). This can be a big cost saving in high-rise building construction.

2.3.9.2 Elimination of the access vestibule for smokeproof exit staircase enclosures

For high-rise building, the exit staircases off the floors located more than 75 feet above the lowest level of fire department vehicle access are required to be smokeproof exit enclosures (IBC 1020.1.7). The access are to the staircase in a smokeproof exit enclosure is required to be form an open exterior balcony (IBC section 909.20.3) or a ventilated vestibule (IBC Section 909.20.4), with a width of not less than 72 inches (IBC Section 909.20.1).

2.4 Problem of fire sprinkler system

Fire sprinkler systems can be used to save lives, property and others benefit, whether they used in industrial buildings, offices, or home. But automatic fire sprinkler systems also present some unique technical problems. Fortunately, such problems can be avoided by knowing the most common reasons for fire sprinkler failure. From the National Fire Sprinkler Association report, the most common reasons for fire sprinkler failure that are error sprinkler activate, overheating, freezing, mechanical damage, corrosion, or leaking.

2.4.1 Problem regarding elements of fire sprinkler

2.4.1.1 Corrosion

Corrosion or rust can weaken pipes and sprinkler heads. The severe corrosion problems have been commonly attributed to microbiologically influenced corrosion and known as MIC. This can result a sudden and unwelcome activation when a sprinkler pipe or head fails. The National Fire Protection Association states that building owners are responsible for replacing sprinkler components that are corroded or rusted.

Corrosion of fire sprinkler piping can lead to potentially hazardous system malfunction, as well as costly water damage and repair costs. Unfortunately, inspections for MIC and corrosion are often overlooked until the problems become serious, such as damaging leaks occur or the corrosion extend to a large areas of the entire fire sprinkler system have to be replaced.

This corrective maintenance approach is a retro-active strategy. The task of the maintenance team in this scenario is usually to effect repairs as soon as possible. Cost associated with corrective maintenance include repair, lost production and lost sales. Repair costs are included replacement components, labour, and consumables.

Solution to corrosion of fire sprinkler

A new proactive approach to fire sprinkler maintenance is available using completely non-invasive, ultrasonic technologies that from the basic of a predictive maintenance approach (Jeffrey, 2005). This approach provides a cost-effective means of detecting the presence and monitoring progression of corrosion and creating a digital record of the system state that can be used to schedule replacement of localized sections of the system before leaks or operation failure occur.

2.4.1.2 Mechanical damage

Fire sprinkler systems depend on the integrity of all their parts. If a sprinkler head is hit or a pipe damaged, the parts can separate and the system cannot be activate when fire is present. A common problem with sprinkler heads is damage from nearby construction of forklifts that are raised too high, accidentally knocking off sprinkler heads. Besides that, installing automatic sprinklers can also result in damage to the system if improper tools or techniques are used (Russell and Fleming, 2000).

Solution to mechanical damage

Fire sprinkler system must always be inspected after the works have been completed by contractor or sprinkler supplier. Homeowner must ensure all elements of the sprinklers in proper manner and without damage.

2.4.2 Problem regarding installation of fire sprinkler

2.4.2.1 Freezing

There are two major kinds of fire sprinkler systems which are wet pipe and dry pipe sprinkler systems. Normally wet pipe sprinkler systems are most common used to install in the buildings. For this sprinkler system, water is constantly maintained within the distribution piping. The advantage to this system is that it responds quickly to a fire and less expensive than other sprinkler systems. The disadvantage to this system is than the water in the system could freeze if installed to freezing temperatures.

The problem that is some inexperience builder installs this type of sprinkler system exposed to freezing temperatures and causes the pipes freeze, the water inside can turn to ice and expand. The expansion can break pipes and fittings, causing leaks and loss of water pressure. The expansion also can force open sprinkler heads, causing accidental activation when the pipes thaw out (Russell and Fleming, 2000).

Solution to pipes freeze

There are three solutions to solve this kind of problem. The first solution to this problem is to run all sprinkler piping inside interior walls and use wall mounted sprinkler heads (Schunk, 2008). The reason of replace ceiling mounted sprinkler heads to wall mounted sprinkler heads is that the space above the ceiling is subject to freezing temperatures.

Another solution to this problem is to mix antifreeze into the water (Schunk, 2008). It will prevent water inside the distribution pipe freeze when water mix with antifreeze. A problem with this solution is that the maintenance requires periodic draining of the system and refilling with the proper mixture. This maintenance is not only expensive but also very messy and difficult to perform in a finished house.

The last solution to prevent freezing is to install the fire sprinkler piping beneath the ceiling insulation (Schunk, 2008). This ceiling insulation must make sure apply to whole area, incomplete ceiling insulation even to a small area will cause the pipe freeze. In additional, insulation is only slows down heat transfer and the pipes will eventually freeze if temperatures changes to very cold.

The best way to prevent this problem happen is that the inexperience builder or homeowner must talk to his contractor or sprinkler sales representative about method to keep fire sprinkler systems from freezing temperatures. From example, the correct method to this problem that is chooses the dry pipe sprinkler system in the freezing temperatures.

2.4.2.2 Overheating

Heat is used to activate fire sprinklers. Fire sprinklers will automatic activate when the heat is detected and no matter the heat will or will not cause the damage to people and property. Where fire sprinkler are located too close to heater, skylights, and other sources of heat, the fire sprinkler can accidentally go off and discharge the water out.

Solution to overheating

According to the rules of National Fire Protection Associated standard 13, installations of sprinkler systems require that higher temperature rated sprinkler be used. This means that the solder elements or glass bulbs used as the operating mechanisms will be designed and replaced with sprinkler heads that are rated for higher heat. For example, normal glass bulbs will activate at temperatures of 68-74 but for higher rate of glass bulbs will activate at temperatures of 93-149 (Russell and Fleming, 2000). If the heat is above this range, a qualified contractor should be hired to make the necessary modifications.

2.4.3 Problem regarding water supply

2.4.3.1 Water supply

A typical domestic water supply for one and two family dwellings includes a 5/8″ water service and meter and may include a water pressure regulator and/or a backflow preventer. All of these devices are designed for a typical residential water flow rate of 5 to 7 gallons per minute. Unfortunately, they cannot deliver the 26 gpm which required by a residential fire sprinkler system. All of these devices need to be increased in size to 1Â¼” in order the water flow rate become 26 gpm (Schunk, 2008).

The problem is, a residential water pressure regulator and water meter that are increased in size to handle the higher fire flows will not properly reduce the water pressure when operating at the low flow rates that are typical in one and two family dwellings (Schunk, 2008).

Solution to water supply

Solution to these problems is to install a seconded larger water service dedicated to the fire sprinkler system. This solution is not only expensive initially, but will have ongoing cost because many water purveyors’ have a minimum monthly rate per meter. The minimum monthly rate mean even there is no consumption but also support to pay certain minimum amount. Also, the rates typically increase with the size of the water meter, so the fire sprinkler meter rates will be more then the rates for the domestic water meter. Again, adding a seconded larger water service and meter is a hidden cost that is because it is part of the plumber’s job, and therefore not included in the fire sprinkler contractor’s bid (Schunk, 2008).

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