Here it says that the process engineering symbols adheres to ANSI/ISA 5.1.

https://www.lucidchart.com/pages/tutorial/p-and-id 

Does anyone know if there is a library for ISO 10628? 

Hi Anders

Thanks for chiming in! 

At this time there isn't any ISO 10628 shapes available from your Shape library. However we're always looking for ways to improve Lucidchart and your feedback is the best way for us to do that. Would you mind adding your request to our feature request form? Ideas submitted to this form are passed on to the product development team for their consideration so that they can improve Lucidchart according to users' needs!

Thank you!

Thanks! Will do.