BDF Underground Fire and Rainwater Tank

A Two compartment bdf tank that serves two duties

The Two compartment bdf tank from LVJIA is a bolted, buried storage tank pressed from bimetallic composite plate at our own plant in Dezhou, Shandong. One excavation, one slab and one shell serve both a sealed fire reserve and a working rainwater store.

What is a Two compartment bdf tank?

A Two compartment bdf tank is a sectional tank assembled below ground from 1000 × 1000 mm pressed panels. Each panel is drawn in a single press stroke from a composite plate: a food-grade stainless layer on the face that meets the water, hot-dip galvanised steel behind it to carry the load. The panels bolt together inside the excavation, so no welding happens on site and no welded seam is ever in contact with the stored water. LVJIA builds this tank from 1 to 1,000+ m³, which means the volume follows the pit you have dug rather than a fixed catalogue size.

How a Two compartment bdf tank divides the volume

An internal bulkhead built from the same pressed composite panel separates the two duties. The fire side carries its own suction and level switch and is never drawn down by day-to-day use; the harvesting side takes the filtered inlet, the first-flush diverter, the overflow and the irrigation or wash-down pump. Because the bulkhead sits on the standard 1 m module, the split can be placed anywhere along the length — a 70/30 division costs the same as a 50/50 — so the fire demand sets the split rather than the tank forcing a compromise.

How the Two compartment bdf tank is built

Three things separate this Two compartment bdf tank from a coated steel tank. First, there is no coating: the corrosion-resistant surface is the stainless face of the panel itself, so there is nothing to blister, peel or repaint. Second, the panel is drawn rather than fabricated, so the water never touches a heat-affected zone where pitting normally starts. Third, every joint is closed with EPDM strip and stainless fasteners outside the water path, which means a single panel can be replaced years later without cutting the tank open. The module is reinforced on all four corners, and the wall is carried on a 16 mm section rated for a full 4.5 m of head.

Technical data for the Two compartment bdf tank

Sizes, panels and capacity

Combined duty pushes the shell larger than either duty alone, so 8 × 4 × 2.5 m, 10 × 4 × 3 m, 12 × 5 × 3 m and 16 × 6 × 3 m are the usual arrangements. Each compartment gets its own sealed, vented manhole so the fire side can be inspected without opening the harvesting side.

Testing, standards and certification

Every Two compartment bdf tank is filled and held at full head for 48 hours before it leaves the factory, and no joint is allowed to weep. The composite plate carries drinking-water contact report SP2630499 from the Dezhou Institute of Product Quality Standards and Metrology, and the plant holds ISO 9001 with CE marking on the product. Copies of the report and the certificate ship with the order, and you can see the full set on our certifications page. The same specification is published on our Made-in-China storefront, where LVJIA is an audited supplier.

Where the Two compartment bdf tank is used

• Warehouses — a large roof feeds the harvesting side while the fire side stays sealed and full.
• Schools and campuses — irrigation and WC flushing off harvested water, sprinkler volume alongside.
• Water-scarce regions — every millimetre of roof rainfall is worth storing when mains water is metered.
• Industrial estates — one excavation covers both the fire authority and the utility bill.

How to order a Two compartment bdf tank

Pricing for the Two compartment bdf tank starts at US$200 per cubic metre, falling to US$180 from 10 m³ and US$150 from 50 m³, FOB Tianjin or Qingdao. The minimum order is one set. Samples ship in 3 to 5 days and batch orders in 15 to 25 days from Dezhou, Shandong, on wooden pallets. Send the roof area and the fire demand in cubic metres and the split comes back on the arrangement drawing. LVJIA holds a 5.0 Alibaba store rating with a response time under one hour.

Send the pit dimensions and the volume you need and LVJIA returns an arrangement drawing and a panel schedule before you commit to anything. If you would rather talk it through first, our engineers answer specification questions directly through technical help, and the rest of the range sits on the BDF underground water tank page.

Other LVJIA tanks worth comparing

If the material has to change, the glass fused to steel tank is the same tank in glass-fused-to-steel, for sites where the surface must never be relined, while the SMC water tank for hotels builds it in moulded GRP. Elsewhere in the BDF underground range there is the anti corrosion BDF tank for aggressive process liquids and the BDF rainwater storage tank for harvested rainwater.

1–1,000+ m³

Built to order

15–25 d

Batch lead time

0–100 °C

Water temperature

• Bimetallic panel. — A food-grade stainless face to the water, hot-dip galvanised steel behind it for strength — pressed in one stroke, not laminated.
• Nothing welded wets. — Panels are drawn, not fabricated, so the water never touches a heat-affected zone where corrosion starts.
• Bolted and gasketed. — EPDM strips and stainless fasteners close every joint, so a panel can be replaced without cutting the tank open.