Storage cylinders containing compressed natural gas at 200 bar require fail-safe control valves. Modern automatic electric CNG cylinder valves integrate multiple mechanical and electronic safety shut-off systems directly onto the tank port.
Triple-Layer Safety Mechanisms
Thermal Pressure Relief Device (T-PRD): Automatically vents gas safely in the event of external vehicle fire when ambient temperatures exceed ~110°C.
Excess Flow Valve (EFV): Instantly seals the outlet port if gas pipe rupture occurs down-line.
12V Electric Solenoid Valve: Automatically keeps the tank isolated whenever the vehicle ignition is switched off.
Frequently Asked Questions
How does an Excess Flow Valve prevent gas discharge?
An Excess Flow Valve uses a internal spring-loaded piston. If fuel line pressure drops abruptly due to a break, high flow pushes the piston closed instantly.
Are CNG cylinder valves reusable during cylinder hydrostatic re-testing?
Valves should be thoroughly inspected, seal-checked, and serviced with new O-rings during mandatory periodic cylinder hydro-testing before being re-installed.
