What is your recommendation schedule for vent line opening inspection?

We would not open the vent system to inspect the internal piping without a good reason.

It is recommended to check for water in the vent stack trap

1. At startup and daily during startup.
2. On LH2 tank system, every delivery
3. After the 1st rainstorm after a system is installed
4. LH2 vent stacks after establishing the baseline above
   1. After every large venting event
   2. Quarterly unless baseline requires more frequent
5. GH2 stack after baseline
   1. Check caps are still on quarterly for stationary tubes.