MCAC-VTSM-2011-09
Installation
Refrigerant Piping Installation
97
No.
Phase (phase-in pressurization)
Criteria
1
Phase 1: appear large leakage after over three minutes of pressurization with 3.0kgf/cm
2
.
No pressure drop
after modification
2
Phase 2: appear major leakage after over three minutes of pressurization with 15. 0kgf/cm
2
.
3
Phase 3: appear small leakage after over 24 hours of pressurization with R410A: 40.0kgf/cm
2
.
3.2.2.2. Pressure observation
1. Pressurize to regulated value and maintain 24 hours. When modifying pressure according to variation
of temperature, it is qualified if pressure drop does not happen. If pressure falls, find out the leak source
and modify it.
2. Modification method
When ambient temperature difference is ±1
℃
, the pressure difference shall be ±0.1 kgf/cm
2
.
Modification formula: Real value = pressure of pressuri (temperature of pressurization
–
temperature during observation) x 0.1 kgf/cm
2
You can find out whether the pressure drops or not by comparing the modification value with
pressurization value.
3. General ways for searching leak source
Conduct detection through three phases; find out leak source when pressure drop happens.
1) Audition detection-----hear large leakage sound
2) Hand-touching detection-----place hand at the joint of pipeline to feel whether there is leakage
3) Soap water detection-----bubbles shall burst out from leak source.
4) Detection by use of halogen leak detector
Using halogen leak detector when finding out pressure drop but not finding the leak source.
a. Keep nitrogen at 3.0kgf/cm
2
.
b. Supplement refrigerant to 5.0kgf/cm
2
.
c. Use halogen leak detector, methane leak detector and electric leak detector for detection.
d. If the leak source still could not be found, continuously pressurize to 40.0kgf/cm
2
(R410A) and then
detect again.
4. Caution
Indoor unit
MS
Nitrogen
Nitrogen
Liquid pipe
Low pressure gas pipe
Liquid side of
shut-off valve
Gas side of
shut-off valve
Gas side of float valve
Pressure meter connector
Nitrogen
High pressure gas pipe
Pressure meter connector
