What is the max allowable pressure for the natural gas system installed with semi-rigid Type K copper tubing?

The maximum allowable pressure for a natural gas system using semi-rigid Type K copper tubing is indeed 2.0 psi. Type K copper tubing is often used for natural gas distribution due to its durability and resistance to corrosion. When installed according to code and manufacturer specifications, it can safely handle operating pressures up to 2 psi.

Understanding the pressure limits is crucial for safety and compliance with regulations. Operating above these limits can lead to the risk of leaks or ruptures, jeopardizing the integrity of the gas system. This is why standards are in place to ensure that materials are used within their tested and approved pressure thresholds.

While examining the other options, it's important to note that pressures above 2.0 psi would exceed the safety guidelines established for Type K copper tubing, which is why they are not viable choices for this application.