When unattended, what safety feature must CNG compression equipment include?

CNG compression equipment must include an automatic shutdown control when unattended for several crucial safety reasons. This feature is designed to respond swiftly to any anomalies or unsafe conditions that may arise during the operation of the equipment, such as pressure fluctuations, leaks, or equipment malfunctions. The automatic shutdown control acts as a fail-safe mechanism that immediately stops the operation of the compressor to prevent potential hazards, such as explosions or fires, which can occur due to the flammable nature of natural gas.

Having this automatic control ensures that even in the absence of personnel, the system can protect itself and the environment from incidents that might compromise safety. This proactive approach is essential in maintaining safety standards and ensuring compliance with regulations governing CNG operations.

In contrast, while standard pressure gauges, advanced monitoring systems, and manual shut-off valves may contribute to safety and operational efficiency, they do not provide the immediate response capability that an automatic shutdown control offers in an unattended setting.