Bulk DEF Storage Tanks and Containment for Fleet Fueling
Bulk DEF storage tanks hold diesel exhaust fluid for fleet yards, truck stops, mobile fueling companies and DEF distributors. Bailiff Enterprises, Inc. manufactures HDPE DEF tanks, double-wall tanks and containment basins in Willis, Texas, and ships nationwide. HDPE is a standard material for DEF because DEF corrodes copper, brass, zinc and aluminum. The keys to good DEF storage are clean materials, temperature control and a closed system.
What DEF is and why storage matters
DEF is 32.5% high-purity urea in deionized water. It must meet ISO 22241-1 to protect a truck’s SCR system. ISO 22241-3 covers handling, transport and storage. Contaminated DEF can damage the SCR system and cause engine derates. Look for the API Diesel Exhaust Fluid Certification Mark on the fluid you buy.
Best material for DEF tanks
Bailiff’s chemical compatibility chart rates HDPE, polypropylene and PVDF Excellent for DEF. HDPE is the practical choice for bulk DEF because it is clean, lightweight and the lowest cost. Keep these out of the wetted path:
- Copper and brass
- Zinc and galvanized steel
- Aluminum
- Carbon steel and iron
Use DEF-compatible stainless steel or plastic fittings, pumps and hoses. Use dedicated DEF-only equipment. Never use a tank or hose that held fuel, oil or another chemical.
Temperature: freezing and shelf life
DEF freezes at about 12°F (-11°C). DEF expands when frozen, so leave room in the tank and never freeze a sealed, full container. After thawing, follow the DEF supplier’s guidance on checking quality. Heat shortens shelf life. Caterpillar lists 15°F to 77°F as the ideal storage range.
The figures below are the commonly published ISO 22241-3 minimum shelf-life values for DEF held at a constant temperature:
| Constant storage temperature | Expected minimum DEF shelf life |
|---|---|
| Up to 50°F (10°C) | About 36 months |
| Up to 77°F (25°C) | About 18 months |
| Up to 86°F (30°C) | About 12 months |
| Up to 95°F (35°C) | About 6 months |
Shelf-life values are guidance, not a guaranteed service life. For Texas and Gulf Coast heat, shade the tank and turn inventory over regularly.
Keeping DEF clean
- Use a closed fill and dispense system where you can.
- Fit a filtered breather on the vent to keep dust and moisture out.
- Rinse new parts with DEF or deionized water, not tap water.
- Label fill points clearly so no one puts diesel in the DEF tank.
DEF secondary containment
DEF is nonflammable. Spill, environmental and handling requirements depend on the jurisdiction and installation, and many sites still require containment, especially next to fuel storage or near drains. Bailiff offers 575-, 625-, 650- and 1,150-gallon containment basins; ask for current stock and confirm the basin suits your installation. Bailiff also makes double-wall tanks, including 550-, 1,000-, 1,550- and 2,500-gallon sizes. Ask which double-wall size fits your DEF volume, and confirm containment rules with your authority having jurisdiction.
Sizes for fleets and distributors
Most fleets use about 2% to 3% as much DEF as diesel. A yard burning 10,000 gallons of diesel a week uses about 200 to 300 gallons of DEF. Bailiff HDPE tanks run from 550 to 10,000 gallons, so you can size for your bulk delivery. Every tank is water-tested before it ships.
What to send for a DEF tank quote
- Weekly diesel or DEF use
- Bulk delivery size
- Indoor or outdoor, and coldest and hottest site temperatures
- Single wall, double wall or containment basin
- Fill, dispense, vent and level gauge locations
- Pump and dispenser make, if known
- Quantity, destination and required date
Frequently asked questions
Is HDPE safe for DEF storage?
Yes. HDPE is a standard material for DEF storage. Bailiff’s chart rates it Excellent.
Can I store DEF in a steel or galvanized tank?
No. DEF corrodes carbon steel, zinc, copper, brass and aluminum. Use HDPE or stainless steel.
What happens if DEF freezes in the tank?
DEF can be used after it fully thaws if its quality is still within specification; follow your DEF supplier’s guidance. DEF expands when frozen, so leave room in the tank and plan for heat in cold climates.
Can a former fuel tank be used for DEF?
No. Leftover fuel or oil contaminates DEF and can damage the SCR system. Use a dedicated DEF tank.
Is DEF the same as diesel fuel?
No. DEF is a water-based urea solution. It is not a fuel, it does not burn, and it goes in its own tank on the truck. Diesel is a combustible fuel covered by fire codes. Never store or transfer DEF and diesel in the same tank, hose or pump. This page covers DEF storage only. Do not assume a DEF tank or its components are suitable for diesel fuel.
Further reading
Request a Bulk DEF Tank Quote
Send your fluid specification, temperature, capacity, fittings, containment and delivery location for a project-specific quote from Bailiff Enterprises, Inc. in Willis, Texas.
General guidance only. Confirm suitability for your fluid, temperature and installation with Bailiff before purchase.
