There are rubber hoses that connect to the fittings. Thanks, that inspection camera will keep me from cutting the end off the tank to look.
I appreciate the help guys, I have about 16 of these to repair.

OK. picture worked. This part is not prepared for welding yet. The cracks are all either in the weld or in the formed insert itself. It varies.

Hope i did the picture correctly.

I have a some large aluminum diesel fuel tanks to repair. I don't have a problem with the welding but the cracks are all in the same place and i'm wondering what the problem is. On the bottom there is a small formed plate with the outlet and return line couplngs welded in. This plate is inset and we...