To realize a pipe joint for a freezing cycle capable of minimizing refrigerant leakage quantity by forming a first airtight member for communicating to an atmospheric air side with a plastic material which barely permeates CO2 refrigerant.
A female joint 20 has a fitting recessed part 24 and a male joint 10 has a fitting projecting part 14 and a step part 13. In the pipe joint for the freezing cycle, the male joint 10 and the female joint 20 are fit by fitting a backup ring 30 and an O-ring 31 at a position adjoining the step part 13 and the fitting projecting part 14, the backup ring 30 and the O-ring 31 are fit into the fitting recessed part 24. In the pipe joint for the freezing cycle, the O-ring 31 is formed with an elastic material excellent in anti-blister characteristics against the CO2 refrigerant and the backup ring 30 is formed with a resin material which is plastically deformable by refrigerant side pressure applied to the O-ring 31 and has a smaller permeability coefficient for the CO2 than the O-ring 31. Thus, the refrigerant leakage quantity can be suppressed to a minimum.
| JP4121182 | Pipe fitting |
| JPS51121647 | AN ELLASTIC PACKING FOR SEALING |
TOMATSU YOSHITAKA
SHIOUME OSAMU
GOMUNO INAKI KK