Refrigerant Pipe Airtight Testing Method - Mitsubishi PUMY-P60NKMU Technical & Service Manual

10-2. REFRIGERANT PIPE AIRTIGHT TESTING METHOD

(1) Connect the testing tools.
• Make sure the stop valves A B are closed and do not open them.
• Add pressure to the refrigerant lines through the service port C of the liquid stop valve A and the stop valve B.
(2) Do not add pressure to the specifi ed pressure all at once; add pressure little by little.
1 Pressurize to 0.5 MPa (5 kgf/cm²G), wait 5 minutes, and make sure the pressure does not decrease.
2 Pressurize to 1.5 MPa (15 kgf/cm²G), wait 5 minutes, and make sure the pressure does not decrease.
3 Pressurize to 4.15 MPa (41.5 kgf/cm²G) and measure the surrounding temperature and refrigerant pressure.
(3) If the specifi ed pressure holds for about one day and does not decrease, the pipes have passed the test and there are no
leaks.
• If the surrounding temperature changes by 1 °C, the pressure will change by about 0.01 MPa (0.1 kgf/cm²G). Make the nec-
essary corrections.
(4) If the pressure decreases in steps (2) or (3), there is a gas leak. Look for the source of the gas leak.
A
C
D
E
F
C
G
OCH502C
B
A Stop valve <Liquid side>
B Stop valve <Gas side>
H
C Service port
D Open/Close section
E Local pipe
F Sealed, same way for gas side
I
G Pipe cover
H Do not use a wrench here.
Refrigerant leakage may result.
I Use 2 wrenches here.
106