EPA 608 Core · Leak Detection · Easy
What gas should be used for safely pressurizing a system to leak test?
Answer: D. Dry nitrogen.
- ACompressed air.
- BPure oxygen.
- CCarbon dioxide.
- DDry nitrogen.✓ Correct
Why D is right
Dry nitrogen is an inert gas, making it safe for pressurizing and leak testing.
More Core questions
- Which leak detection method is best for pinpointing an exact leak location?
- What is a 'trace gas' used in leak detection?
- What is the most effective way to detect a massive system leak quickly?
- How does an ultrasonic leak detector find a leak?
- When searching for a leak with an electronic detector, how should the probe be moved?
Go deeper with the study guide AIM Act 2026: The HFC Leak Repair Rules for HVAC Techs, try the free 10-question test or browse all EPA 608 practice questions.
A practice question written for study, checked against 40 CFR Part 82, Subpart F. It is not an official EPA exam question, and this site is not affiliated with the U.S. EPA.