What does an inspector observe about an oil storage tank serving a furnace?

An oil storage tank is inspected the way any accessible vessel is: for how it is holding up, how it is held up, and whether anything is escaping. Condition means surface corrosion, pitting, weeping at seams and — for outdoor or basement tanks — deterioration at the bottom where moisture collects, since tanks usually corrode from the inside out and the first external sign is often a damp patch or staining. Support means legs bearing properly on a stable surface, since a tank that shifts stresses its supply and fill lines. Evidence of leakage includes staining beneath, odour, and discolouration of the surrounding floor or soil. What the inspector cannot do is quantify remaining fuel meaningfully, judge wall thickness without measurement, or say anything about the fuel itself, so those all lie outside the visual examination.

The inspection covers what can be observed: the tank's condition, how it is supported, and any evidence of leakage or staining. Those are the conditions that indicate whether the tank is serviceable and whether fuel is escaping.

Fuel oil tanks are examined visually for corrosion, seam weeping, support adequacy and evidence of leakage. Tanks commonly corrode internally from accumulated water, so external evidence may appear late. Buried tanks are outside a visual inspection entirely.

Condition, Support, Leakage. Three visual questions. Anything requiring a gauge, a meter or a lab is somebody else's.

Ask about buried tanks. An abandoned underground tank is a significant environmental liability and is entirely outside the inspection, so noting the question is valuable.

• •Attempting to assess wall thickness or remaining life by eye
• •Overlooking tank support and the stress it places on supply lines
• •Failing to raise the question of a possible buried tank