Precision Fuel Solutions
We get quite a few inquiries about fuel tank pressure testing. While it is a very good method to find out if a tank is leaking, it is not a good way to assess the condition of the tank. Also, unless a tank has been removed so all sides can be checked, a pressure test will not even tell you where the leak is. When it comes to fuel tanks, or most tanks for that matter, pressure testing is really only effective at assuring a new tank has been constructed well or that a tank repair is sound.
The problem with using pressure testing to find the condition of a tank is that it will not tell you how badly corroded and pitted a tank is inside or out. An aluminum, steel, or even stainless tank may have areas of pitting that are corroded almost all the way through and still easily hold the 3-4 psi of a pressure test.
While we're on the subject of tank tests that are sometimes used to assess a tanks condition, another one is ultrasound. Ultrasound is great for checking the thickness of materials over a larger area, like the hull of a steel or aluminum vessel, but can easily miss the type of pitting that will usually lead to a tank leak. This type of pitting is often deeper than it is wide. That means, even if you can reach the area of the tank most likely to leak, the bottom, the pits will likely be missed.
Both pressure and ultrasound tests are very useful to diagnose certain other fuel system/tank problems, just not the overall condition of a tank. PFS uses these tests and others when they will provide useful information about a tank or fuel system. Tests like these are very good at diagnosing things such as leaks in fuel lines/connections or larger areas of a tank with thinning from internal or external corrosion.
Other tools sometimes helpful in assessing a tank/fuel system are vacuum testing and using an inspection camera for things like finding restrictions and examining external corrosion. However, unless a tank is already very clean inside, and very well lit an inspection camera will tell almost nothing useful about internal corrosion.
The fact is, the only way to accurately assess the condition of a "used" tank is to empty it, clean it, and visually inspect and gauge the extent/depth of the internal corrosion as well as the external condition. To accomplish this usually involves installing access plates if the tank does not already have them.
We believe that when we're finished a reliable fuel supply is not something a captain should have to worry about.
A clean, sound tank + clean leakfree fuel lines+clean fuel and filters= Peace of Mind
Tank and Fuel System Testing and Inspection