What is the required characteristic of pipes, tubing, fittings, gaskets, and packing material used in CNG service?

The required characteristic of pipes, tubing, fittings, gaskets, and packing material used in CNG service is that they must be compatible with the fuel under the maximum service conditions. This is crucial because any material that is not compatible with CNG can lead to deterioration or failure, resulting in leaks or other hazardous situations. Compatibility ensures that the materials can withstand the chemical properties of compressed natural gas, including its pressure, temperature, and potential interactions with other substances.

Choosing materials that are specifically suited for CNG service not only helps in maintaining the integrity of the system but also ensures safety for drivers, vehicles, and the environment. The system can endure the demanding conditions it may encounter during operation, assuring reliability and efficiency in CNG transportation and delivery.

The other options do not meet the essential requirements for ensuring safety and operational integrity in CNG systems, highlighting the importance of material compatibility as the primary concern in these applications.