| 摘要 |
It is an objective to achieve suppressing progress of electrolytic corrosion (galvanic corrosion) by aluminum or an aluminum alloy caused by diffusion of copper ions to a connection pipe formed of aluminum or an aluminum alloy. The copper ions are diffused through water having condensed and staying in a small gap between the thermally insulating material and the connection pipe. In a gas pipe 30 and a liquid pipe 40 of a connection pipe unit 20, connection portions 37 and 47, in which aluminum pipes 31 and 41 (first refrigerant pipes: refrigerant pipes formed of aluminum or an aluminum alloy) and copper pipes 32 and 42 (second refrigerant pipes: refrigerant pipes formed of copper or a copper alloy) are respectively connected to each other, are disposed in fall portions of the aluminum pipes 31 and 41. The connection pipe unit 20 is covered with a thermally insulating material 60. An anti-corrosion treatment is applied to the aluminum pipes 31 and 41 covered with the thermally insulating material 60. |
