You can merge equipment and none of the visits will be lost. All the visits on the duplicate move across to the equipment you keep.
Start from the equipment you want to keep:
1. Open the site and click into the equipment record you want to keep.
2. In the Equipment Details box, click the small arrow next to "Edit Equipment Details" and choose "Merge equipment".
3. A list of equipment opens. Search for the duplicate and click "Select".
4. You'll be asked to confirm. Click to go ahead.
The duplicate's visit history is then moved onto the equipment you kept, and the duplicate is removed.
A couple of things to watch for:
Make sure you start from the record you want to keep. The one you pick from the list is the one that gets removed.
Only the history moves across, not the duplicate's own details (serial number, notes and so on). If the duplicate has the better details, copy them onto the one you're keeping before you merge.