LPG vs PNG vs CNG Gas Detectors: Which One Do You Need?

Published by Gas Kavach Team | March 2025 | 7 min read

One of the most common mistakes people make when buying a gas detector is assuming all gas detectors are the same. In reality, LPG, PNG (piped natural gas), and CNG are different gases with different properties, and each requires a different type of detector - or at least a detector calibrated for that specific gas. In this guide, we break down the key differences to help you choose the right detector.

Understanding the Three Gas Types

LPG (Liquefied Petroleum Gas)

LPG is a mixture of propane and butane. It's the most commonly used cooking fuel in Indian homes, supplied in familiar red cylinders by companies like HP, Bharat Gas, and Indane. LPG is heavier than air - when it leaks, it sinks to the floor and accumulates in low-lying areas.

PNG (Piped Natural Gas)

PNG is essentially methane (CH4) delivered through underground pipelines directly to homes and buildings. It's increasingly common in Indian metro cities like Mumbai, Delhi, Pune, and Ahmedabad through companies like Mahanagar Gas, IGL, and Adani Gas. PNG is lighter than air - when it leaks, it rises to the ceiling.

CNG (Compressed Natural Gas)

CNG is the same gas as PNG (methane) but compressed to high pressure for use as vehicle fuel. CNG detectors are used in auto garages, CNG filling stations, and vehicles running on CNG. Like PNG, CNG is lighter than air.

Key Differences: LPG vs PNG vs CNG

Property	LPG	PNG	CNG
Composition	Propane + Butane	Methane	Methane (compressed)
Weight vs Air	Heavier (sinks)	Lighter (rises)	Lighter (rises)
Detector Placement	Near floor (30cm high)	Near ceiling	Near ceiling
Sensor Type	Semiconductor / Catalytic	Semiconductor / Catalytic	Semiconductor / Catalytic
Typical Use	Homes, restaurants, hotels	Piped gas homes, buildings	Vehicles, filling stations
Supply Method	Cylinders	Underground pipeline	High-pressure tanks
Explosive Range	1.8% - 9.5%	5% - 15%	5% - 15%

How to Choose the Right Detector

For LPG Cylinder Users (Most Indian Homes)

• You need an LPG gas leak detector
• Install it 30cm above the floor, near the cylinder or stove
• Look for models with loud alarm (85dB+) and optional solenoid valve shutoff
• Our recommendation: Gas Kavach Domestic LPG Detector or GV 108 LPG Detector (with auto shutoff)

For Piped Natural Gas (PNG) Connections

• You need a methane / natural gas detector
• Install it near the ceiling, within 1-2 meters of the gas inlet point
• Ensure the detector is calibrated for methane (CH4)
• Some LPG detectors also support methane - check specifications before buying

For CNG Vehicles & Stations

• You need a CNG/methane gas detector
• For vehicles: Install our Auto Gas Alert System
• For CNG stations/garages: Use industrial fixed gas detection systems with multi-point monitoring

For Commercial Kitchens & Restaurants

• Need depends on your gas supply - LPG manifold system or PNG pipeline
• Commercial kitchens typically need multi-channel industrial gas detection panels (like GV 108 or GV 09 series)
• These provide centralized monitoring with auto solenoid valve shutoff and exhaust fan activation

Common Mistakes to Avoid

1. Buying the wrong detector - An LPG detector won't effectively detect PNG leaks and vice versa
2. Wrong placement - LPG detectors near the ceiling or PNG detectors near the floor are practically useless
3. Installing too far from the source - Place the detector within 1-4 meters of the gas source
4. Ignoring calibration - Gas detectors need annual calibration to maintain accuracy
5. Buying uncertified products - Always buy detectors with proper certifications (CE, ISI)

Conclusion

Choosing the right gas detector starts with understanding what type of gas you use. LPG, PNG, and CNG each have different properties that affect how they leak, where they accumulate, and what type of sensor detects them most effectively. When in doubt, consult with a gas safety expert before making a purchase.