Safety - Safe Adolescence

Author: Han Shi, Shang Jinlong
Publisher:
Publish Date: 2006-07-01
Features:
Four, Firefighting Precautions for Gas Fires In urban and some rural areas of China, gas fuel has become widespread. Currently, the primary gas fuels used in households are natural gas and liquefied petroleum gas. When these gases burn incompletely, they produce odorless and colorless carbon monoxide, a toxic gas that is difficult to detect. Therefore, gas fuels are odorized before being supplied to users so that leaks can be identified early. The most common causes of liquefied gas fires are leaks from the following four places: the connection between the gas cylinder nozzle and the pressure reducer; leaks in the gas pipeline and hoses; leaks from the appliance; and failure of the main gas valve.
Points to Note for Safe Gas Use:
(1) Regularly check whether the liquefied gas cylinder and appliance are leaking. If a leak is detected, immediately open windows and doors to ventilate, cut off all fire and electrical sources, and move the gas cylinder to a safe location.
(2) Always follow the sequence of lighting the flame first and then opening the gas valve (except for electronic ignition stoves). Someone should supervise during use to prevent the flame from being extinguished by spills or wind, which could cause a large amount of gas to leak and lead to an explosion upon contact with an open flame.
(3) Gas cylinders should not be placed near heaters or fireplaces. Always close the valve on the gas cylinder after use. Never handle or pour the residual liquid from the cylinder into the drain.
(4) In the event of a fire, close the valve on the gas cylinder, unscrew the pressure reducer, or cut the hose, and move the cylinder to a safe outdoor location.
If a liquefied petroleum gas cylinder catches fire during use, first remain calm and take immediate action. Under normal circumstances, if the gas cylinder valve is closed and the gas supply is cut off, the flame will gradually extinguish. If the valve fails, use a wet towel, mud, or soap to temporarily block the leak, then move the cylinder to an open area to allow it to vent naturally. To prevent burns when closing the valve on an empty cylinder, wear a water-soaked glove or wrap your hand with a wet towel, turn sideways, keep your face away from the flame, and close the valve in a clockwise direction.
When a gas cylinder is on fire, you may hear a whistling sound. Do not panic, as long as the cylinder remains upright, liquefied petroleum gas will not flow out and intensify the fire. The cylinder will not explode if the surrounding temperature does not exceed 60°C and the cylinder is still standing. In most cases, the temperature around the cylinder is unlikely to rise to the explosion threshold. Never tip over the cylinder, as this will cause the liquefied petroleum gas to flow out through the nozzle, expand rapidly by 250–300 times into gas, and participate in combustion. The high temperature from the intense flame will increase the internal pressure of the cylinder, causing it to deform or burst, leading to an explosion.
If the cylinder is knocked over, immediately move it upright and close the valve. While sand, dry powder extinguishers, etc., can put out the flame, they cannot stop the gas from leaking out. Ventilate the area to prevent the accumulation of liquefied petroleum gas. If the cylinder bursts and a large amount of gas leaks, a white mist may form in the vicinity. In this case, it is crucial to cut off all fire sources in the area and nearby to prevent an explosion. If the fire is large and difficult to control, quickly call for help, move flammable objects away, and contain the spread of the fire. Move the cylinder out of the fire scene as soon as possible to prevent it from exploding due to heat.