The Dangers of “Dual Gas Mixing”!

“Dual gas mixing” refers to the mixing of natural gas and other gas sources (such as liquefied petroleum gas) indoors, the storage of liquefied petroleum gas cylinders in rooms with piped natural gas, and the use of gas appliances that are incompatible with the gas source.

Why shouldn’t dual gas be used?

1. Density and Diffusion Conflict:

Natural gas (methane): Density is lower than air. Leaks diffuse upward and tend to accumulate near ceilings.

Liquefied petroleum gas (propane/butane): Density is higher than air. Leaks deposit downward and tend to accumulate on the ground or in low-lying areas.

Contradiction: When mixed, the two gases may form “stratified accumulations” in the space, making them difficult to fully detect with conventional detectors.

2. Appliance Incompatibility:

Nozzle Diameter: Natural gas appliances have larger nozzle diameters (suitable for low pressures), while liquefied petroleum gas appliances have smaller nozzle diameters (suitable for high pressures). Mixing gas can lead to:

Using natural gas with liquefied petroleum gas appliances: The flame is too small, resulting in incomplete combustion and the production of carbon monoxide;

Using liquefied gas with natural gas appliances: The flame is too large, causing backfire or deflagration.

3. Explosive chain reaction: Mixing can expand the explosion range, multiplying the risk of explosion. A leak or explosion in one source can instantly detonate the other source, endangering the entire building!

What are the dangers of “mixing two gases”?

1. Storing unused liquefied petroleum gas cylinders at home can easily lead to accidental openings, causing leaks. A single mistake can cause an accident.
2. Using a gas appliance that is incompatible with the gas source not only results in problems like misfires and gas leakage, but also in incomplete combustion, producing carbon monoxide, which can lead to poisoning and other dangerous consequences.
3. Using both natural gas and liquefied petroleum gas in a home can greatly increase the risk of combustion or explosion, as the two gases can detonate each other. This can significantly increase the risk and severity of the accident, with unimaginable consequences. 04 When using both natural gas and liquefied petroleum gas (LPG) simultaneously, if a leak occurs, it’s difficult to immediately determine which gas is leaking, making it difficult to take timely action, greatly increasing the risk.

How to use gas correctly?

01 Never mix two gases. Never use LPG or other fuels simultaneously in a room that also uses piped natural gas. Users with piped natural gas should immediately clean their LPG cylinders and replace their gas appliances with natural gas-compatible ones.

02 Gas appliances must be compatible with the gas source. Natural gas and liquefied petroleum gas differ in calorific value, density, and pressure, and their corresponding stove designs are also different. Therefore, gas appliances with different gas sources cannot be interchanged. Never continue to use old appliances after changing gas sources to save money.

03 Develop good gas usage habits. When using gas, maintain good ventilation and have someone supervise the area. After daily use, turn off the appliance and gas valve. Turn off the main valve when not in use for extended periods.

04 Install a home gas alarm for constant protection. Home combustible gas detectors are professional instruments that monitor gas leak concentrations in real time. Compared to relying on smell (natural gas leaks smell like rotten eggs), listening, or using soapy water, a home gas alarm acts as a more sensitive “electronic nose,” offering higher detection accuracy, more timely audible and visual alarms, and continuous operation. It is the “guardian” of household gas safety.

From “passive response” to “active prevention”

1. For proper installation, the gas alarm should be mounted on an indoor wall within 4 meters horizontally and 2 meters away from the gas appliance or gas source, in a well-ventilated area.

★ When detecting gases lighter than air, such as natural gas, the alarm should be mounted 0.3-0.6 meters from the ceiling.

★ When detecting gases heavier than air, such as liquefied petroleum gas, the alarm should be mounted 0.3-0.6 meters from the ground.

★ When detecting carbon monoxide: The alarm should be mounted within 1.5 meters of the gas appliance, close to the breathing zone.

Note: Avoid installing gas alarms in the following locations:

• Areas with high airflow, such as ducts;
• Areas subject to mist or dripping water;
• Areas near stoves that are easily contaminated by fumes, steam, and other pollutants, or in high-temperature environments (such as directly above the stove);
• Areas obscured by other objects (such as inside cabinets);
• Near vibrating objects such as refrigerators and air conditioners.

02 Regular Maintenance

◆ Household gas alarms require regular annual inspections, at least once a year.

◆ According to relevant standards, the service life of a typical residential gas alarm is five years. Upon expiration, they should be replaced promptly.

◆ If dust is noticeably visible on the surface of the gas alarm, gently wipe it with a damp, soft cloth. Be careful not to use a cloth that is wet with water.

◆ After cleaning, perform a self-test. Only reinstall and continue using it if the test is normal.

◆ During maintenance and cleaning, never use chemicals such as alcohol, gasoline, or detergents to clean the alarm, as this may damage the device.

Gas safety is paramount; detection and early warning are crucial. Mixing natural gas and liquefied petroleum gas (LPG) not only lacks convenience but also poses significant safety risks. Only by raising safety awareness, improving detection methods, and strictly adhering to operating regulations can “convenience” be transformed into “true safety.”