Refrigeration cycle apparatus and leakage inspection method for refrigerant piping of refrigeration cycle apparatus

A leakage inspection method for refrigerant piping of a refrigeration cycle apparatus that includes:

• a compressor;
• a condenser;
• an expansion valve;
• an evaporator;
• a piping cover provided with at least one a leakage inspection port configured to allow a gas to flow from inside of the piping cover to outside of the piping cover;
• refrigerant piping that is at least partially covered with the piping cover, connects the compressor, the condenser, the expansion valve, and the evaporator, is configured to circulate a refrigerant, and includes at least one joint joined by brazing or welding;
• a housing containing the compressor, the condenser, the expansion valve, the evaporator, the refrigerant piping, and the piping cover;
• and a pair of constrictors configured to sandwich the at least one joint and the at least one leakage inspection port and narrow a gap between the piping cover and the refrigerant piping,
• the leakage inspection method comprising:
• filling the refrigeration cycle apparatus with a leak detection gas excluding air as the gas until pressure becomes higher than atmospheric pressure;
• detecting concentration of oxygen at the leakage inspection port or concentration of the leakage detection gas at the leakage inspection port;
• and
• determining whether leakage occurs at the joint based on a detection result of the detecting.