Air Tightness Test - Mitsubishi Electric R410A Service Handbook

[1-3 Working with Refrigerant Piping ]
1-3-2

Air Tightness Test

No changes have been made in the detection method. Note that a refrigerant leak detector for R22 will not detect an R410A leak.
1. Items to be strictly observed
Pressurize the equipment with nitrogen up to the design pressure (4.15MPa[601psi]), and then judge the equipment's air tight-
ness, taking temperature variations into account.
Refrigerant R410A must be charged in its liquid state (vs. gaseous state).
2. Reasons
Oxygen, if used for an air tightness test, poses a risk of explosion. (Only use nitrogen to check air tightness.)
Refrigerant R410A must be charged in its liquid state. If gaseous refrigerant in the cylinder is drawn out first, the composition
of the remaining refrigerant in the cylinder will change and become unsuitable for use.
3. Notes
Procure a leak detector that is specifically designed to detect an HFC leak. A leak detector for R22 will not detect an
HFC(R410A) leak.
HWE14080
Halide torch R22 leakage detector
- 10 - GB