ISO 7320:2021 establishes a system for sealing the port connection of couplings used in the aerospace industry.
It specifies dimensions to achieve interchangeability of the port connection, the fitting end and a seal. The seal can be a standard O-ring or a special ring.
![ISO 7320:2021](https://www.365standards.com/wp-content/uploads/2023/03/ISO-7320-2021-770x660.png)