What is the necessary requirement for horizontally installed containers?

The necessary requirement for horizontally installed containers is that they shall not be in direct contact with each other. This guideline is important for safety and operational integrity. Keeping containers separated helps manage risks associated with pressure relief, fire hazards, and accidental leaks. Isolation prevents any potential chain reactions that could occur in the event of a failure in one container impacting neighboring containers, thereby ensuring that each unit can operate safely and effectively independently.

While other options may seem plausible, they do not capture the critical safety concern addressed by the requirement regarding direct contact. For instance, containers being coated with protective paint may help in corrosion resistance but does not significantly impact safety in the way separation does. Installing containers in a single row or stacking them are not standard practices endorsed for safely storing horizontally installed containers. The emphasis on not allowing direct contact underscores the focus on mitigating risk and enhancing safety protocols in handling and storing CNG.