Confidence: Verified against CAN/ULC standard scopes and Ontario Fire Code Part 4.
The single most-confused yard-tank question: which ULC standard does my tank need to be built to? The answer depends on the service, not the appearance of the tank.
| Standard | Scope | Typical use |
|---|---|---|
| CAN/ULC-S601 | Shop-fabricated steel aboveground tanks for flammable and combustible liquids — single- and double-wall horizontal cylindrical tanks for diesel and gasoline | Yard tanks for on-road clear-diesel fleet refuelling; cardlock dispensers; commercial bulk diesel |
| CAN/ULC-S602 | Aboveground steel tanks for fuel oil and lubricating oil — maximum capacity 2,500 L, single-wall and secondary-containment | Generator base tanks; basement heating-oil tanks; lubricating oil day tanks |
Related: CAN/ULC-S603 is the underground tank standard; ULC-S655 / S653 / S652 cover protected, contained, and used-oil tank assemblies.
op-on-farm-bulk-diesel-storage-compliance.The Ontario Fire Code, Part 4, Section 4.3.1.2(1) lists the acceptable aboveground-tank standards: API SPEC 12B/12D/12F, API STD 650, CAN/ULC-S601, S602, S603, S603.1, S615, S652, S653, S655, ULC/ORD-C142.20. Selection from this list is driven by service, not by tank shape.
Any aboveground installation under O. Reg. 217/01 requires a TSSA-certified Petroleum Mechanic holding a PM.3 certificate (O. Reg. 216/01). See reg-oreg-217-01-liquid-fuels and reg-oreg-216-01-petroleum-mechanics.
This distinction is the most-confused item in customer conversations about yard tanks. Marketing-page copy on tank installation should lead with the operator's situation ("a yard tank to fuel your trucks") and let the standard live in the source footer. Quoting an S602 tank for a clear-diesel application — or letting a customer buy one online expecting B&J to hook it up — produces a non-compliant install.