How to Read the Gas Cylinder Code

Understanding the codes on your LPG gas cylinder is not just about logistics—it is a critical safety measure for your home. While many refer to these markings as "expiry dates," they are technically "Test Due Dates" that indicate when a cylinder must be sent back for a mandatory safety inspection.

Here is a full breakdown of what codes like A24 and B26 mean and how to read them.

🔍 How to Read the Gas Cylinder Code

The code is always found on one of the three vertical metal stays (the bars connecting the body to the top ring) of the cylinder. It consists of one letter (A, B, C, or D) and two digits.

1. The Letters (The Quarter)

The year is divided into four quarters, each represented by a letter:

Letter	Quarter	Months Covered
A	1st Quarter	January – March
B	2nd Quarter	April – June
C	3rd Quarter	July – September
D	4th Quarter	October – December

2. The Digits (The Year)

The two numbers following the letter indicate the year in which the cylinder is due for testing.

24 = 2024
26 = 2026
30 = 2030

💡 Real-World Examples

A24: The cylinder was due for a safety check between January and March 2024. If you receive this today, it is "expired" or overdue for testing.
B26: The cylinder is scheduled for testing between April and June 2026.
D25: The cylinder is safe to use until the end of December 2025.

⚠️ Why the "Expiry Date" Matters

LPG cylinders are made of steel and store gas under high pressure. Over time, factors like humidity, rough handling, and chemical reactions can weaken the metal or the valve.

The Testing Process Includes:

Hydrostatic Test: Checking if the cylinder can withstand high internal pressure without leaking or deforming.
Pneumatic Test: Checking for minor leaks in the welds.
Visual Inspection: Checking for deep rust, dents, or damage to the foot ring.

Important Note: A cylinder "expires" on the last day of the quarter mentioned. For example, a cylinder marked B26 is considered valid until June 30, 2026.

🛡️ Safety Checklist for Consumers

Check the Code on Delivery: Always look at the inner side of the metal stays when the delivery person arrives.
Refuse Overdue Cylinders: If the year on the cylinder has already passed (e.g., it's 2026 and you get a cylinder marked C25), do not accept it. It is illegal and unsafe for the distributor to supply an overdue cylinder.
Check the Seal: Ensure the plastic seal over the valve is intact and has the official hologram of the gas company (HP, Bharat Gas, or Indane).
The Soap Test: If you smell gas, apply a bit of soapy water to the valve. If bubbles form, there is a leak.