Heat pump 50Hz/R410A _ 6
2. Guideline for each installation process
Part 3 Design and installation
2.2 Refrigerant piping work
2.2.1 Principles of refrigerant piping
The “ principles of refrigerant piping “ must be strictly observed.
Air tight
Clean
Dry
Action to avoid problemCause of problem
-Rainwater, work water, etc
 gets into pipes from outside 
-Moisture generated inside pipe 
 due to condensation
-Formation of oxides inside 
 pipes during soldering
-Dirt,dust or other extraneous 
 material gets into pipes from outside 
-Leak from soldered area
-Leak from flared area
-Leak from flange area
Pipe coveringFlushing  Vacuum drying
Replace Nitrogen
Pipe covering
Pipe covering
Flushing
Use the proper materials
Adhere strictly to standard soldering work practice.
Adhere strictly to standard flaring work practice.
Adhere strictly to standard flaring connection work practice.   
• The end of all copper pipes should be capped to protect them from dust or water particles while safe keeping 
The 3 princples of refrigerant piping work
Dry Clean Air tight
Make sure there is no moisture inside 
the pipes
Make sure there is no dirt inside the 
pipes
Make sure the refrigerant does not 
leak out.
Moisture
Dirt
Leak