stevesh is right... You can use the image map (aka "hotspots") to point to any URL you like.

If you have a schematic image of a pump, set it up using the <map></map> protocol, and for each "hotspot" the URL will read something like:-

HTML Code:
index.php?main_page=product_info&cPath=336_347_348&products_id=2846
... where this is the PATH to the specific pump component referenced by that "hotspot".

To find out what these URL's are, just open each component "product" info screen in your browser. Then look at the Address Bar... you'll see the path, just copy and paste for each URL...