I suggest that you make a formula date field to calculate the Next Inspection Anniversary Date. I'm not sure how this might vary between different types of equipment, but for example if it was always a certain number of years from the Inspection Date, then you can have a field to enter that # of years (perhaps defaulting to 1) and then have a formal field
[Next Inspection date] which is a date formula field of
AdjustYear([Inspection date],[# year between inspections])
Then you can make various reports with filters such as
where
[Next Inspection Date] is on or before 30 days in the future