Not an engineer, but I'd think a tank would rupture by being over-pressured, more so than developing a leak.
Am an engineer, but not an air tank engineer. So I’ll write in general terms.
The difference between a leak and a catastrophic failure is 1) progression and 2) time. A catastrophic rupture is usually a fatigue failure caused not only by corrosion but by pressure cycles in that corroded and compromised state. A catastrophic failure requires a compromised area that is continuous— or continuous enough to propagate once initiated.
If a tank is leaking due to corrosion, it is scrap. The point of leakage is just the canary in the coal mine— there are certainly main OTHER points of the tank (at a similar water level) that are about ready to fail.
In other words, barring weld defects or bad fittings, a tank is NEVER bad in just one spot, even if its only actually leaking in one location. ASME cert all but guarantees the welds are fine.
In a home garage situation, the risk of tank rupture is extremely low. Not zero, but low enough you shouldn’t worry about it. Most home compressors simply haven’t ingested enough air (and hence water) to sustain the amount of corrosion needed to compromised an ASME-cert tank. In home use, the timeframe is decades in most cases.
Grab a large rubber mallet and whack the tank. It should resonate like a metal drum. If there are any parts that do not, then borescope the tank, easily done through the several ports on most.
Pressure testing is nice to do, but it’s just a moment in time. A tank can test fine on a pressure test and leak the next year if it was used a lot in that year in a super humid area and never drained. This is why ASME actually over-pressures the tanks when it tests them (120% I think).
There’s no replacement for diligent monitoring.
I’ll take a 20 year old USA-made industrial tank (like a champion) over a brand new box store chinese tank every time. The former starts out more likely to have weld quality problems, and will be much more sensitive to the inevitable corrosion that comes because it’s lower gauge material with lower quality fabrication.
My water management plan comes down to two primary countermeasures: a tank drain on a timer that I can turn off and on (briefly burping the drain while in use at regular intervals (say 30 min) and then disabling this when not in use. Secondly, I’m not plumbing my compressor head directly to the tank. I’ll be plumbing it to the shop piping with moisture traps and cooling provisions and then feeding the tank off the shop piping. This provides time for the air to cool (and condense) before it hits the tank.
You can do the aftercooler/transmission cooler thing if you want, or you can do the overkill and overpriced copper pipe water trap things if you want. But just dumping the hot air into a point distant from the tank is often quite sufficient.
