How much CNG can a manufacturer introduce into a newly constructed container for testing purposes?

The correct answer reflects the regulations and practices in place for testing newly constructed containers intended for storing compressed natural gas (CNG). When a manufacturer introduces CNG into a newly constructed container, the permitted amount for testing purposes is typically determined to ensure safety and compliance with industry standards.

In this context, 500 cubic feet of CNG serves as a practical volume that provides a sufficient quantity for the necessary pressure testing and inspections without posing excessive risk. This volume allows manufacturers to accurately assess the integrity of the container, verifying that it can withstand the pressures it will encounter during usage. Testing with this volume aligns with safety protocols and helps ensure that the container meets all regulatory requirements before it enters service.

Knowing the correct amount for testing purposes is critical, as introducing excessive volumes could lead to dangerous situations or exceed safety limitations, while an insufficient volume might not provide enough data for a proper assessment of the container's readiness.