Fuel Tanks & Day Tanks
Fuel tanks and day tanks store diesel for a standby generator, either as bulk storage sized for a project's full autonomy requirement or as a smaller day tank feeding the engine directly. NLS sources bunded bulk tanks and day tanks built to NFPA 30/31 for hospital, industrial, and commercial standby power projects across Saudi Arabia.
A generator's fuel system usually splits into two tanks: a bulk storage tank sized to hold enough diesel for the project's required autonomy (the number of hours a generator has to run without refueling), and a smaller day tank mounted near or on the genset itself, which the bulk tank refills automatically as the engine draws fuel down. Separating the two keeps the tank feeding the engine small and close, so fuel pressure and flow stay consistent, while the bulk tank does the heavy lifting on storage volume and delivery-truck refill frequency.
NLS sources tanks built to NFPA 30 (flammable and combustible liquids) and NFPA 31 (oil-burning equipment) as the reference standards for construction, venting, and secondary containment, in single-wall with a separate bund wall or double-wall (integrally bunded) construction. Double-wall tanks are increasingly the default specification on Saudi projects since the outer wall gives secondary containment without a separate concrete bund, which simplifies site layout and civil defense sign-off. Capacity runs from a few hundred liters for a small day tank up to tens of thousands of liters for a bulk tank sized against a hospital's or data center's full autonomy requirement.
NFPA 110 sets the autonomy requirement that sizes the bulk tank on a hospital or life-safety project: a Level 1 emergency system typically needs a minimum of 2 hours of on-site fuel by code, though many Saudi hospital project specifications call for 8, 24, or even 72 hours of autonomy depending on how remote the site is from a reliable resupply route. Day tank sizing follows a simpler rule: enough capacity to run the genset at full load for roughly 30-60 minutes, giving the bulk tank's transfer pump time to respond to a low-level signal without the engine running dry.
Sourcing works the same as NLS's other categories: send the required autonomy hours, the genset's fuel consumption rate at full load, and whether the project needs single-wall with a bund or double-wall construction, and NLS returns a priced quote in USD with a lead time based on tank capacity and fabrication. Standard double-wall day tanks in common sizes typically source faster than large custom-fabricated bulk tanks, which need a fabrication lead time from the manufacturer.
Specifications
- ✓Built to NFPA 30 (flammable and combustible liquids) and NFPA 31 (oil-burning equipment) as reference standards
- ✓Construction: single-wall with separate bund, or double-wall (integrally bunded) for secondary containment
- ✓Bulk tank capacity sized to project autonomy requirement (hours of full-load fuel consumption)
- ✓Day tank capacity typically sized for 30-60 minutes of full-load runtime with automatic level-controlled refill
- ✓Fittings: level gauge, high/low level alarm, vent, and overfill protection
- ✓Material: mild steel with internal/external coating, or GRP for smaller day tanks
Frequently Asked Questions
How many hours of fuel autonomy does a hospital generator need in Saudi Arabia?+
NFPA 110 sets a 2-hour minimum for a Level 1 emergency system by code, but many Saudi hospital project specifications call for 8, 24, or 72 hours depending on how far the site sits from a reliable diesel resupply route. NLS sizes the bulk tank against whichever number the project's specification requires, not the code minimum alone.
What's the difference between a bulk fuel tank and a day tank?+
The bulk tank holds the project's full fuel reserve, sized for the required autonomy hours. The day tank is a smaller tank mounted near the genset that feeds the engine directly and gets refilled automatically from the bulk tank as it draws down, keeping fuel pressure to the engine steady.
Who supplies bunded fuel tanks for generators in Saudi Arabia?+
NLS sources and supplies single-wall bunded and double-wall integrally bunded fuel tanks, built to NFPA 30/31, for hospital, industrial, and commercial generator installations across Saudi Arabia.