FITTINGS: Here is one of our welded Vanguard fuel tanks; the series of port holes you see are the fittings for the fuel tank, these comprise of fill ports, emergency vents, interstitial monitoring and more. These provide critical functions for a fuel tank. On the left is one in its rawest form, while on the right it is ready to be dispatched to our client. Find out more about a critical vent on a fuel tank, the emergency vent in the article via the link.