Why Combustible Gas Detectors Are Necessary

PureAire Combustible Gas Detectors are indispensable safety devices that continuously monitor and detect flammable and explosive gases before they reach dangerous levels. These detectors provide early warning of gas leaks or accumulations that could otherwise go unnoticed until a fire or explosion occurs.

Many combustible gases, such as methane, propane, or hydrogen, are colorless, odorless, and tasteless, making them undetectable without a gas detector. In industrial, commercial, and manufacturing environments, this creates serious safety risks. Installing a reliable combustible gas detection system is one of the most effective ways to protect people, equipment, and facilities.

A combustible gas detector is essential when:

• The work environment involves flammable gases or vapors
• There is a risk of gas leaks from equipment, piping, or storage
• Facilities must meet fire codes, OSHA requirements, and local safety regulations

Knowing when and where to install combustible gas detectors is key to preventing unnoticed gas buildup and avoiding costly downtime, injuries, or catastrophic incidents.

How Do Combustible Gas Detectors Work?

Combustible gas detectors use Lower Explosive Limit (LEL) sensors to detect and measure flammable gases in the air. The LEL represents the minimum concentration of gas required to ignite or explode when exposed to an ignition source. The sensor detects this threshold and, when it does, triggers an alarm.

How LEL Sensors Detect Gas

1. Sensing – The LEL sensor continuously samples the surrounding air and detects the presence of combustible gases.
2. Signal Processing – The sensor converts gas concentration data into electrical signals, typically using 4–20 mA outputs or relay contacts, which communicate with control panels, ventilation systems, alarms, horns, and strobes.
3. Alerting – When gas levels approach unsafe thresholds, the system activates audible and visual alarms to warn personnel to implement safety protocols or evacuate the area.

Fire Code Compliance and Regulatory Requirements

Installing combustible gas detectors is often required to comply with fire, building, and safety regulations. While requirements vary by jurisdiction, many standards mandate continuous monitoring in environments where flammable gases are present.

NFPA 72 – National Fire Alarm and Signaling Code sets standards for fire alarm systems, including gas detection when integrated with alarm systems.

• NFPA 72 requires that gas detector equipment installed on a fire alarm system be listed and installed in accordance with applicable code sections, and that the detector location and engineering evaluations be documented.
• Although the newest fuel gas detection provisions have been moved into NFPA 715 (Standard for the Installation of Fuel Gas Detection and Warning Equipment), NFPA 72 remains the principal code for interfacing gas detectors with fire alarm systems.

NFPA 70 – National Electrical Code (NEC) governs electrical installations, including those in hazardous (classified) locations where flammable gases are present. The code requires appropriately listed and rated equipment for Zone/Division classifications and may specify that gas detection systems must:

• Be listed for the specific gas to be detected
• Be installed as point or area detectors with no temporary or portable wiring
• Include proper alarm and shutdown criteria based on combustible gas thresholds (e.g., LEL percentages)

NFPA 30 – Flammable and Combustible Liquids Code, which recommends continuous monitoring in areas with spill or leak risks.

Choosing the Right Combustible Gas Detector

Selecting the right combustible gas detector depends on both the application and the environmental conditions.

Key Factors to Consider

• Explosion-Proof (EXP) Ratings for hazardous locations
• Ingress Protection (IP) Ratings for resistance to dust and moisture
• Sensor lifespan and calibration requirements
• Compatibility with existing alarm and control systems

The combustible gas detector should be durable, reliable, and designed to perform in the conditions where it will be installed. Proactive installation helps reduce liability while improving workplace safety, but always consult local and state authorities for the most current regulations.

Why PureAire Combustible Gas Detectors Stand Out

PureAire Monitoring Systems’ MPS Combustible Gas Detector (LEL) delivers continuous, real-time monitoring of flammable gases. The easy-to-read display shows current gas levels, while integrated alarms alert personnel immediately if unsafe concentrations are detected.

 

Key Benefits of PureAire Combustible Gas Detectors

• Explosion-proof enclosure designed to prevent ignition
• Measures 14+ combustible gases
• Long-life Molecular Property Spectrometry (MPS) Sensor 100% TrueLEL sensor lasting 15+ years
• Audible and visual alarms (horns and strobes)
• Zero calibration required
• Proven reliability in industrial and commercial applications

Frequently Asked Questions (FAQs)

What gases do combustible gas detectors detect?

PureAire combustible gas detectors can detect many flammable gases, including methane (natural gas), propane, hydrogen, ethane, ethanol, butane, acetylene, isopropyl alcohol (IPA), and isobutyl. Refer to the product summary for a complete list.

What does LEL mean on a gas detector?

LEL stands for Lower Explosive Limit, which is the minimum concentration of a flammable gas that can ignite. For many gases, this level is below 4% by volume, meaning even small leaks can pose serious risks.

How do explosion-proof gas detectors work?

Explosion-proof gas detectors use LEL sensors housed in specially designed enclosures that prevent ignition, even if gas enters the detector. These systems safely detect combustible gases and activate alarms without creating an ignition source.

Do I need a combustible gas detector?

If your facility uses, stores, or produces flammable gases, a combustible gas detector is essential. It provides early warning of dangerous gas levels, helping prevent fires, explosions, and injuries. These risks are especially dangerous because gas leaks often occur without warning, reinforcing the need for continuous gas monitoring in industrial and commercial settings.

How do combustible gas detectors help with code compliance?

Many fire and building codes require combustible gas detection in specific areas. Installing a compliant detector helps meet regulatory requirements while improving overall safety.

What should I consider when selecting a gas detector?

Consider your application, environmental conditions, required certifications, and maintenance needs. Choosing a reliable detector with long sensor life reduces downtime and ongoing costs.