Delhi | September 10, 2026
Delhi government officials said vehicles with expired or unavailable CNG cylinder hydro-test certificates will not be allowed to refuel, as authorities tighten enforcement following an August 19 cylinder explosion that killed three workers and seriously injured three others.
The mandatory hydro test must be carried out every three years under Rule 35(1) of the Gas Cylinder Rules, 2025 Amendment. The test determines whether a cylinder can safely withstand the high pressure at which compressed natural gas is stored and is required for CNG vehicles operating in the capital.
Indraprastha Gas Limited has launched a special verification drive at its CNG stations, according to a senior official. Station personnel have been instructed to check the validity of hydro-test certificates before allowing vehicles to refuel. Vehicles whose certificates have expired, or owners who cannot show the certificate, will not be refuelled under the enforcement exercise.
A hydro test involves emptying the cylinder, filling it with water and subjecting it to very high pressure. The process is intended to identify leaks, cracks or swelling that may not be visible during a routine inspection. CNG is stored in vehicle cylinders at pressures of about 200 to 250 bar, and repeated use, pressure changes and exposure to road vibrations can affect the cylinder over time, officials said.
The hydro-test certificate is the official document confirming that a cylinder has passed the prescribed high-pressure water test and is considered safe for use. Vehicle owners have been asked to keep the certificate in their vehicles and ensure that testing is completed on time.
The enforcement follows the explosion of a truck’s CNG cylinder during refuelling on August 19. The incident killed three workers at the pump and left three others seriously injured. The report did not provide further details about the cause of the explosion or identify the station where it occurred.
Officials said vehicle owners must have their cylinders tested at a centre approved by the Petroleum and Explosives Safety Organisation in accordance with the applicable rules. IGL has urged owners to complete the test within the prescribed cycle and retain proof of certification when visiting CNG stations.
The current enforcement action places responsibility on both vehicle owners and refuelling personnel to verify that cylinders meet the required testing standard before gas is dispensed. The special verification drive is now under way at IGL-operated CNG stations in Delhi.
