EPA Section 608 Universal Certification ExamType III (Low-Pressure Appliances)Medium
A technician is leak testing a low-pressure chiller after repairs. Which of the following pressure ranges is acceptable for pressurizing the system with controlled nitrogen for leak detection, without causing damage?
- A50 to 60 psig
- B0 to 5 psig
- C10 to 20 psig
- D30 to 40 psig
Show answer & explanationAnswer & explanation
Correct answer: B. 0 to 5 psig
Low-pressure systems, especially those using refrigerants like R-123, have very low design pressures. Pressurizing with nitrogen for leak testing should be done carefully to avoid damaging the system. A pressure range of 0 to 5 psig is generally considered safe and effective.
Why the other options are wrong
- A. 50-60 psig is extremely dangerous for low-pressure equipment.
- C. 10-20 psig can potentially damage a low-pressure system's components like rupture discs.
- D. 30-40 psig is far too high and will likely cause significant damage.
Low-Pressure Leak Test Pressure
The maximum safe pressure used to pressurize a low-pressure system with nitrogen for leak detection.
- Must be kept very low to prevent damage.
- Typical range is 0-5 psig.
- Exceeding this can rupture diaphragms or burst discs.
Memory trick: Low pressure, low PSI, don't blow it high!