Maintenance and Repair of Firefighting & Fire Alarm Systems
Introduction
All of us are familiar with three factors,Heat, Burning material and Oxygen and we know that as long as these three factors put together ,the burning will happen and its continuously,so for preventing fire and if the fire happened, for preventing of progress of fire , should be ready.
Necessity of Maintenance and repair of Firefighting systems in buildings To achive the above case,Performing various types of Fire alarm and fire extinguishing systems in Different buildings are necessary but more important is ready of these systems ,for fire and fulfill the assigned duties in the danger zone. Therefore,after Correct performing of these systems,Maintenance and periodic repair and peridoic handling to Equipment and their availability for working , is great importance. Hamyar Sanat company with experts and professional Technicians in the field of maintenance of Fire alarm and Firefighting
Systems , in addition to offer suitable and professional services in this field, also has achieved to customers's satisfaction. Below is summary of maintenance and repair plans of Hamyar Sanat company.
Maintenance and repair of Firefighting system. As you know maintenance and repair, the set of activities and actions to prepair for the deployment equipment at the acceptable Level in terms of operation (Maintenance) or restore the defective equipment to the used cycle and exploitation and the expected result of these actions,create readiness and maintain operational capability , continuos
operation of equipment for defined terms.
NFPA25 Standard for Inspection ,Testing and Maintenance of Water-Based fire protection systems,completely inspection , test ,Maintenance and repair of these equipments and all the necessary measures to provide and maintenance the system in the same Operating condition. In wet pipe sprinkler system, the sprinklers connected to the plumbing network and once the sprinkler activated, the water is immediately discharged. The advantage of this system , can be mentioned high speed and low installation costs, Maintenance and repairs. In most areas ,where there is no risk of freezing,wet wipe system is the first choice of designers and ensuring the correct operation and maintaning favorable condition of firefighting extinguishing system only by carrying out a proper process of maintenance and repair will be obtained effectively.
Inspection,Test and repairs
1-Inspection
Sprinklers: Sprinklers should be visited annualy, and free of any corrosion (rust),color,External material and physical damage and suitable to their type ( upright , pendant or sidewall) should be install correctly, and if they have any of the above problems, should change ,and correct the situation. and any obstruction and clogging of the path to it, will also be eliminated. In the case of service and maintenance of spare parts and inventory, the following should be checked annually.
1-Fit the number and type of sprinkler
2-Spining wrenches for sprinklers used in the system.
- (Pipe and fitting) Pipes and fittings used ,should be controlled every year and in good condition.Free of mechanical damage,leakage,corrosion and irregularity (Non-Conformance) and there is no external burden on them.
-(Hangers and seismic Braces) materials and size of pipe,type of building materials,probability of earthquake occurrence and ,etc .... are the factors that influence on the choice of the type of closures and the distance between them. In the inspection process, it should be noted that none of the preservatives be physically damaged or unsteady. In the case of damage or unsteady, the necessary action is to replace or attach to them.
-(Gauges): All barometers should be visited monthly to maintain their proper status and accurately display the water supply pressure of the network.
-(Buildings): Every year the start of the cold season, all parts of the building where sprinkler's fire extinguishing system has been installed. Including wall and ceiling windows, doors, air conditioning, ventilation , ..... inspects the water in the sprinkler system For freezing, and the amount of heating (energy) required to create a minimum temperature of 4.4 C .
- (Alarm devices) : These equipments, including :mechanical and power supply switches and ,... should be reviewed once every three months and verified without any physical damage.
-( hydraulic system) : Should be check every three months.
-(Hose Connection) :According to the standard ,should visited and check yearly.
-(Control valves):It should be noted that at least one listed control valve should be installed on any sprinkler system. Unless the sprinkler system feeder and firefighting firebox water network (Systems consisting of a plumbing network and fitting for fire extinguisher hoses used for mannual extinguishing) be the same, so the control valve should install to each floor.
Until the repair of sprinkler's system, there is no disruption to fire performance of the water network , the above mentioned valves,Including Butterfly valves, and etc....,should be checked weekly and monthly.
Test
(Sprinklers): High quality sprinklers will work well and if no physical damages occure , it does not require testing for up to 50 years ,But then they have to be replaced or tested. in the second case, randomely from different regions, some cetain numbers are selected as sample and sent to a qualified laboratory in the field of control of performance and testing of these equipment. Once verified, they will be usable and then this process will be repeated every 10 years. If the sprinkler is 75 years old, the distance Between each control will reduce to 5 years.
(Gauges) : These equipment should be replaced every 5 years or compared to a calibrated sample and in the absence of precision so that it can be sent to the calibration unit.
(Alarm devices): These equipment should be tested as expected and should be reviewed every three months and verified with out any physical damage, and according to the standard ,should have functional testing.
(Hose connection):After five years from the time of installation,these equipment should be tested and if approved, then every three years this will happen.
Repairs
In the fire extinguishing system, the following is done: Sprinklers : In some parts of the sprinkler systems, the restoration of the complex is carried out in the framework of
the modernization of equipment and components :
-Type of sprinkler
-Orifice size and K Coefficient
-Tempreture Rate
-Sprinkler cover (If it has)
- Type (upright,pendant,sidewall)
-Design requirement
In special box,there should be a number of spare sprinklers that is suitable with the types used in the system.The location of the box above is not exposed to moisture,dust,corrosion or tempretures above 38 C. It should not use the sprinklers with spray paint or any other decorative or non - standard decorations.
Condition of spare sprinkler's number that should be stored,are as follow:
-In systems with sprinkler less than 300 Number, at least 6 Sprinklers
-In systems with 300 - 1000 Sprinklers, at least 12 Sprinklers
-In systems with more than 1000 Sprinklers, at least 24 Sprinklers
(Sprinkler wrench) : In the implementation of the repair process , one of the most important and required tools is sprinkler's wrench, For each type of installed sprinkler on the system,there should be a special wrench in the spare box to be used during assembly and dismantling of the sprinklers and wrenches.
Installation confirmation test :In the case of repairs of the components and equipment of the sprinkler fire extinguishing system, That has effect on the sprinklers which are more than 20 Numbers, and Installation and commissioning of all of the above elements Must be done according with the standard (NFPA13). Hose connection :After each time , use of this product, all interfaces should be drained , cleaned and completely dry, before re-use In the system.Equipment that failed to recieve at the inspection and testing stages , should be repaired , tested or replaced.
Valves :This Equipment is one the most important key that should be repaired or maitenaced annually or whenever required andSome of its internal elements are being visited.
Marine systems :Usually in sprinkler fire fighting systems, after Repairs,Fresh water is used a supply source for discharging and re-watering the equipment.
Conclusion:
It has mentioned here about Inspecion,Testing and Repair of ( WET SYSTEM) according to the approved standards ,andThe overall design and importance of having a consistent program in this area was identified to increase the efficiency of the systems. Therefore, Hamyar Sanat company ,according to the various condition in buiding will plan to maintenance and repair of
Fire extinguishing systems. Maintenance and Repair of Firealarm system Fire alarm system readiness as the first and most effecive Fire detection system to the inhabitants of the buildings and it has
special importance.
Generally , designing,implementing and exploiting a fire detection system and fire alarm is done in two ways that Protecting people's lives and property.
According to the national building regulations, Section 13 and the Firefighting regulations of fire alarm systems are divided into different categories.
1-Manual systems: In these systems for Fire alrm, only Call point Fire extinguisher are used.
2-Automatic systems:
1-Conventional
2-Addressable
3-Smart
A-Manual type only for buildings ,up to four floors without elevators.
B) For all buildings that are more than four floors, Installation of an automatic Fire alarm system is compulsory.
C)For all public,Commercial,Cultural,Educational Places and ... to install an automatic fire alarm system is compulsory.
Systems Ranking:
Manual:Only use of Fire alarm
Automatic : Manual Automatic detection only for spaces with high Fire risk
Manual Automatic detection of escape routes
Manual Automatic detection of escape routes and rooms leading to escape routes
Manual Automatic detection of high fire risk spaces and sleeping areas
Manual automatic detection of all spaces
zoning:
Ease, speed and precision in detecting and locating the fire, especially in large buildings, makes it necessary to divide the building into smaller and distinct areas. In conventional buildings, we usually consider each floor as a protective zone or zone. In a large building with high floor floors, one floor can be divided into several protective floors.
False Alert
One of the problems with automatic fire alarm systems is to send a wrong and incorrect alert, which, if repeated, will reduce the confidence of the system.
Error messages can be categorized into five groups:
1- Error warnings caused by doing things like cooking, smoke, car exhaust smoke, dust
2- Alarms caused by faults in the network
3. Error warnings caused by extreme actions such as breaking the trigger bars
4. Unknown error alerts that can not be placed in any of the above categories
In conventional systems with 40V or less, two error messages are considered normal and normal in the year Different Types of automatic Fire alarm systems:
1-Conventional systems
2. Addressable systems
3. Smart systems
Conventional fire alarm systems:
In this system, several detectors covering an area of the building are connected in the form of an interconnected circuit and connected to the central control panel, so each orbit represents a region. How to connect the detection and detection equipment to the central control panels is branching and radial. Each conventional control panel can be 4,2-2,12,8-16 zones.
Different modes of Fire alarm system:
1-Open circuit: If the circuit is disconnected at any point, it will reduce or stop continuous flow. This item will alart by the central control panel.
2. Normal conditions: Detectors pass through very little flow, which is the same continuous flow
3. Warning conditions: In the event of fire and activation of the detectors, the current flow is increased and may reach up to 50 mA.
4. Short circuit mode: In the event of a short circuit in the circuit, the potential difference is reached zero and the flow rate is greatly increased. There should not be more than 30 detectors and testers in each conventional zone or branch circuit.
Addressable fire alarm system:
The principles of detecting and detecting fire in addressable systems are similar to conventional systems, except that in such systems, Each automatic detector or call point has a unique address through which the control panel is able to identify it. The circuit of discovery in such systems is circular, which starts from the central control panel and ends on the same board.
All equipment is documented in this loop.
The maximum distance of spaces that can be protected by a loop is 10,000 square feet and can cover up to five areas.
The audio warning circuit can be installed separately.
The maximum number of elements in each loop is 126.
Intelligent Firewall: (Analog Addressable) In intelligent systems, the detector is always active and consistently responds to signals sent from the central control panel, and as the addressable and conventional systems are only in two states of warning or non-alert. In such systems, detectors play the role of testers whose data As input signals to central control panel microprocessors. In order to determine the overall state of the central switchboard, it is thoroughly checked every 5-10 seconds.
Fire alarm system components:
1. Central control panel: The central control panel controls all inputs, controls all output equipment and provides electrical power to all sectors. It is Main power supply of the AC control panel and its DC power supply (battery)
Types of detectors and Fire alarm call point are the control inputs equipment. Sirens, warning lights, lift recall relays are control output devices.
The choice of the central control panel is the type of system chosen, the size of the building, the number of zones and equipment required for the input and output of the fire alarm.
The central boards should be installed at the points of the building where there is a lower risk of fire and at the same time commuter of maintenance staff and control of the building are more there.
Smoke detectors:
These detectors are divided into four categories.
1-optical (optical) 2- ionization 3- Laser 4- Suction
The maximum distance between two smoke detectors should not exceed 10 m
The maximum distance between a smoke detector and a wall should not exceed 5 m
The maximum distance covered by a smoke detector is 50 .
Light Diode Detector :
Most diodes have a Light diode
1- Blink every 9 seconds Normal Condition
2- Continuously lit indicating the detector
3. The light diode remains off or flashes rapidly, indicating a fault in the detector Light diodes are used in most places except places where their smoke is caused by normal work (kitchen-parking).
Beam Smoke Detector:
In this type of detector, there is a light source for a light sensitive cell. If the light radius is interrupted or reflected by light-sensitive light smoke, the detector operates.
Radiation Detectors: In this type of transducer, infrared rays and photovoltaic cells can be used at a distance of 100 meters. In the presence of smoke, the infrared radiation is diminished and the detector operates.
This type of detector is used for large surfaces (length 100 m and width 100 m) and is installed at a distance of 30 to 60 cm below the ceiling and usually Used for warehouses, stores and open spaces.
Channel Light Smoke Detector:
This type of optical smoker detector is installed inside the air channel and installed in the return air direction
Wireless Smoke Detector:
This kind of wireless detector acts like a transmitter with radio waves and sends a signal to the fire alarm center acting as the receiver when it activates
Laser Smoke Detector:
Its function is similar to that of a smoked diode, but instead of Beam smoke diode radius, the radius of a laser beam is used that gives a very high sensitivity to the detector. This type of detector is very precise when detecting dust particles from smoke with a high sensitivity. Smoky ionization detectors work very well in detecting firefighters, but they are not very effective in detecting hidden fires. Smoke detectors are quick to detect hidden fire and are weak in detecting fast fire. Laser detectors are much better at detecting both types of fire.
Ionizing Smoke Detectors:
These detectors have a chamber with two positive and negative electrodes, which cause the presence of a radioactive substance called amouisium to cause ionization of air inside it. Therefore, a weak electrical current is established between the two electrodes in the ionization chamber. The introduction of smoke into the compartment causes the electrical circuit to break down and reduce the electrical current between the two electrodes and the detector is activated.
Inhaler smoke detector:
Inhalation or inaccurate detectors detect the presence of smoke that may be due to fire, based on the sampling of air In a given atmosphere. One or two smoke detectors (lasers) are an electronic board that processes and evaluates Is the main implementation of this kind of detector.
Heat Detector:
Fixed Temperature
Increase Rate
Compound
Place of use: in the kitchen, engine room, parking lot and where there are no places to use the smoke detector due to the types of steam and smoke from natural gas.
Depending on the operation, thermal temperature detectors are divided into three categories.
1-Rapid Reaction
2-Medium Reaction
3-Weak Reaction
Fixed Temperature Thermal Detectors :
This type of detector operates on a predetermined and stable temperature. These types of detectors have a thermocouple or metallic mechanism. Thermal Detectors with increase rate:
Such detectors are driven by the speed of temperature rise. Therefore, the two factors increase the temperature and duration of the action of the effective detector. The excitation rate for most augmentation detectors is usually in minutes, which means that if the temperature is increased within one minute, the detector will be in an alert state.
Compound Thermal Detector:
It is a combination of two detectors , Fixed and increased
Linear Thermal Detector:
Flame Detector:
1. Infrared detector
2. The detector
3- Composite detector (infrared)
This type of detector is capable of detecting infrared and ultraviolet radiation from a flame. These types of detectors should have the ability to detect fire from a distance of 14.1 in an 8.1 square meter area. Flame detectors suitable for wide open spaces or with high roofs like warehouses-hangars Airplanes and industrial enclosures, as well as open or semi-open enclosures where the rapid movement of air or wind can prevent the heat from reaching the detector.
Fire Alarm Call point:
Such changes act as a key and by stimulating someone who has been identified the fire and send a warning signal to the fire alarm center .
Audio warning equipment:
1- Ringtones
2 - Horns
3- Alarms and speakers
Wall Alert Equipment:
Blind and flashing lights, along with audio alarms, inform the residents of the danger of fire.
1. The key is to test the health of the LEDs of the system and restart the system.
2. Turn off siren sound during fire.
3. Turning off the clear sound (small siren inside the device)Malfunctions caused by power failure and battery power Shortages caused by short circuit and circuit of zones
4- Testing the siren of the system
5. If set to Normal, the existing switches are disabled
6. If there are shapes (short circuit / open circuit) on the siren path, it will be clear.
7. When urban power (zzo 220AC) or batteries (Interrupted or damaged or unplugged) will turn on.
8. Normaly it should always be on.
