What conditions prohibit the use of a piping system on a cargo tank?

The answer demonstrates a comprehensive understanding of safety protocols outlined in the NFPA 58 regarding cargo tanks and their associated piping systems. When considering the operational integrity of a piping system installed on a cargo tank, any condition that compromises the integrity of the system is cause for concern.

A leak in the piping system is a critical failure point that can lead to dangerous situations such as gas escape, which poses risks of fire and explosion. Piping that is compromised due to corrosion can weaken the structure, potentially leading to leaks or breaks under pressure, also presenting significant safety hazards. Even if the piping appears new and intact, if there is any suspicion of issues with bolts or other connections that could indicate wear or inadequacy, the system is still not reliable.

In summary, all of these conditions - a leak, corrosion, and concerns about structural integrity - reinforce the necessity of ensuring that a piping system is absolutely safe and operationally sound. Therefore, the prohibition of the use of any piping system under such circumstances is vital to maintain safety and compliance in LPG operations.