Which of the following is considered an acceptable level of leakage for completed assemblies?

In the context of NFPA 99, the acceptable level of leakage for completed assemblies is defined to ensure the safe and effective operation of medical gas systems. The standard specifies that a leakage rate of 0.5% is allowable for completed assemblies, which reflects a balance between safety and functionality. A leakage rate of this magnitude is generally acceptable because it minimizes the risk of gas loss without compromising the pressure and flow rates needed for medical applications.

The choice of 0.5% is based on industry practices and safety considerations, which ensure that even at this level of leakage, the safety of patients and healthcare workers is maintained. Medical gas systems are critical in healthcare settings, and establishing existing parameters such as this one helps prevent potential hazards associated with gas leaks.

While lower leakage rates could hypothetically be seen as preferable, the specified rate ensures that the systems operate within a practical and manageable range, considering real-world installation conditions and operational use. Therefore, 0.5% is recognized as an acceptable threshold to ensure both safety and performance of medical gas assemblies.