Which component is essential for the safety of compressed natural gas systems during pressure changes?

Pressure relief devices are critical for ensuring the safety of compressed natural gas (CNG) systems, particularly during pressure changes. These devices function by automatically venting gas to the atmosphere when the pressure within a system exceeds a predetermined limit, thus preventing potential overpressure conditions that could lead to catastrophic failures, explosions, or damage to the system.

The necessity of pressure relief devices becomes particularly evident during scenarios such as temperature fluctuations, which can cause gas expansion, or during operational issues that can result in an increase in pressure. By providing a reliable means of emergency pressure release, these devices help maintain the integrity of the system and protect against hazards associated with excessive pressure.

Other components, while important for the overall function and safety of the CNG system, do not provide the same level of protection against pressure-related incidents. Valves and regulators play roles in controlling flow and pressure in the system, and storage containers are designed to safely hold the gas under pressure, but they do not actively mitigate the risks related to pressure increases in the same way pressure relief devices do.