Part 3 Fire Safety Equipments
Chapter 2 Alarm Equipments
Section 4 Automatic Fire Alarm Equipments for Gas Leakage
Where automatic fire alarm equipments for gas leakage are used, fire alarm divisions shall be allocated under Article 112.
The above-mentioned gas refers to the following gas fuels:
2.Liquefied petroleum gas (LPG).
3.Other gases designated by the central regulating authority.
Gas leakage detectors shall be installed at proper locations convenient for inspection and repair on the ceiling or wall depending on the characteristics of the gas and pursuant to the following requirements:
1.Where the specific gravity of gas to air is less than 1, the following provisions shall be observed:
(1)Detector shall be installed within a horizontal distance not more than 8m away from the gas burning appliances or from the position the gas pipe goes through the wall. Where the floorslabs have beams with a net height not less than 60cm or other similar constructions, detectors shall be installed just nearby the gas burning appliances or the positions the gas goes through the wall.
(2)Where there are air inlets on the ceiling of the room where the gas burning appliances are, detectors shall be installed within 1.5m away from the air inlets separated by the beams with a net height not less than 60cm or other similar constructions between the gas burning appliances or the location the gas pipe goes through the wall and the ceiling.
(3)The lower end of detector shall be within 30cm under the ceiling.
2.Where the specific gravity of gas to air is not less than 1, the following provisions shall apply:
(1)Detector shall be installed within a horizontal distance not more than 4m away from the gas burning appliances or from the position the gas pipe goes through the wall.
(2)The upper end of detector shall be within 30cm above the floor.
3. The commencing and terminal points for calculating the horizontal distance are as follows:
(1)For a gas-burning appliance, the point is the center of the appliance.
(2)For a position the gas pipe goes through the wall, the point is the center of the gas pipe at the position the gas pipe goes through the wall.
Gas leakage signal receiving switchboard shall meet the following requirements:
1.Gas leakage signal receiving switchboard shall be located in watchroom or other populated places. Where a disaster prevention center is set up, the switchboard shall be located in the center.
2.The alarm division where gas leakage occurs shall be marked.
3.For detectors installed at the position the gas pipe goes through the wall, the alarm divisions shall be marked respectively.
4.The operating switch of wall-mounting switchboard shall be 0.8m~1.5m high from the floor (0.6~1.5m for seat type)
5.The tone color and volume of the main sound device shall be different from other alarm sounds.
6.Where there are two or more gas leakage signal receiving switchboards in a same building, equipments for communication between the two shall be installed at the switchboards.
Gas leakage alarm devices shall comply with the following provisions:
1.Gas leakage indicating lamps shall be equipped pursuant to the following provisions. But it is allowable that no indicating lamp is installed where an alarm division only covers one room.
(1)Where a living room equipped with detector faces the passage, indicating lamp shall be installed nearby the gateway of the proportion facing the passage.
(2)The height of indicating lamp shall be less than 5m above the floor.
(3)The brightness shall enable the lamp to be obviously distinguished at the position 3m in front of the lamp, and “Gas Leakage Indicating Lamp” shall be marked nearby.
2.In the area where gas leakage can be detected by the detector, the alarm device inside this area shall make alarm upon operation of the detector, and the volume shall be not less than 70db at the position 1m away, unless the detecting appliance is provided alarm function, or it is installed in machine room or other places not usually populated or at the position the gas pipe goes through the wall.
Wiring of automatic fire alarm equipments for gas leakage shall comply with indoor wiring specifications.
1.500V DC insulation ohmmeter shall be used to measure the insulation resistance between the wires of power circuit as well as between the wire and the earth. Where the voltage to earth is not more than 150V, the resistance shall be not less than 0.1MΩ; where the voltage to earth exceeds 150V, the resistance shall be not less than 0.2MΩ. And 500V DC insulation ohmmeter shall also be used to measure the insulation resistance between the wires of the detector circuit as well as between the wire and the earth, and the resistance shall be not less than 0.1MΩfor every alarm division.
2.The signal loop of usually opened detector shall employ serial connection, and terminal resistor shall be attached for the gas leakage signal-receiving switchboard to perform automatic detection of disconnection.
3.The circuit loop of detector may not be shared by equipments other than automatic fire alarm equipments for gas leakage.
Battery shall be used as emergency power source for automatic fire alarm equipments for gas leakage, and the capacity of battery shall be able to ensure the two loops effectively run at least for 10 consecutive minutes, and other loops to supervise at least for 10 minutes.
119 fire notification devices shall comply with the following requirements:
1. They shall be installed in watch room or other usually populated places. Where a surveillance center is set up, the switchboard shall be installed in the center.
2. They should provide manual and automatic actuating function.
3. When setting up the remote starting device, there should be a device that can communicate with the people where the 119 fire notification device was set.
4. The operation switch of the manual actuating device shall be installed at higher than 0.8m and lower than 1.5m from the ground.
5. The transmitter and receiver should be set up and clearly distinguished from other intercom calls near the device.
6. They shall not be installed aslant, and shockproof measures shall be taken.