What is the maximum test pressure for pressurizing Type III centrifugal systems using nitrogen?

In Type III systems, which typically involves low-pressure refrigerant applications, the maximum test pressure for pressurizing with nitrogen is established at 10 psig. This value is crucial for ensuring the integrity of the system without causing damage to the components, which can occur if the pressure exceeds the manufacturer's recommendations or the system's design limits.

By using nitrogen for pressurization, technicians can perform leak testing safely, as nitrogen is inert and does not pose any risk of reacting with the materials in the system. Keeping the pressure at or below 10 psig protects sensitive components and allows technicians to accurately identify leaks without risking system failure or damage. Thus, the specific designation of 10 psig aligns with safety standards and best practices in HVAC service and maintenance, ensuring both effective testing and the longevity of the system being serviced.