Texas CNG(Compressed Natural Gas) Driver Practice

What should pressure relief valves for CNG service not be fitted with?

1. Manual operation controls

2. Lifting devices

3. Pressure gauges

4. Emergency shutdown systems

The correct answer is: Lifting devices

Pressure relief valves are critical components in CNG service systems, designed to prevent excessive pressure buildup within storage tanks and pipelines. These valves automatically release gas when the pressure exceeds a predetermined limit, ensuring safety without the need for manual intervention. These valves should not be fitted with lifting devices because doing so could compromise their essential function. Lifting devices might enable manual operation or alterations to the valve's operation, which would negate the automatic safety features that relief valves provide. The purpose of a relief valve is to function independently in response to pressure changes, making manual controls unnecessary and potentially dangerous. In contrast, options like manual operation controls, pressure gauges, and emergency shutdown systems can provide safety and monitoring functionalities without interfering with the automatic nature of the relief valve. These elements can work alongside the pressure relief valves to enhance overall safety and operational efficiency without compromising their critical automatic pressure regulation functions.