Engineer-specified plastic tanks for sulfuric acid (H₂SO₄) storage and dosing service. Industrial Plastics fabricates HDPE, PVC-U, PP-H and PVDF tanks for sulfuric across the range where plastic is the right material, and tells you plainly where it isn’t.
Material selection for sulfuric acid tanks
Sulfuric acid storage is a duty where material selection turns on concentration and temperature, not chemistry alone. The same material that handles 32% sulfuric at 25°C without complaint will char and stress-crack in months at 78%, or at 60°C. Get the SDS and the operating temperature in front of an engineer before anyone selects a wall thickness.
- HDPE (PE100): Handles dilute sulfuric (under ~50%) at ambient temperature reliably. The standard, cost-effective choice for water-treatment pH-adjustment and dosing tanks holding diluted sulfuric.
- PVC-U: One of the most chemically stable plastics we fabricate, and it holds sulfuric across a wide concentration band at ambient. Hard, cheap and easy to weld, but it has a low heat ceiling (around 60°C) and resistance gets contested at the very top of the range, so it suits cool, indoor dilute-to-moderate duties. Outdoor service needs a UV-stabilised grade.
- Polypropylene (PP-H): Extends service into the mid-concentration range with better temperature and outdoor durability than PVC. Common for mining and mineral-processing duties running 50 to 70% sulfuric. Note that PP loses headroom as temperature rises, so hot mid-concentration service needs checking case by case.
- PVDF: The fluoropolymer option for high-concentration sulfuric. PVDF holds up well into the 90s% at ambient and cool temperatures, but its window narrows sharply with heat: at 96 to 98% it is rated only to around 65°C, and above that it moves from marginal to unsuitable.
Below ~50% and ambient, HDPE is the default. The hotter and more concentrated the duty, the further up the material ladder you climb, and at the top of that ladder, plastic runs out.
Send the SDS, the concentration, the operating temperature, the fill cycle and the service life. We confirm material selection (HDPE / PVC-U / PP-H / PVDF), wall thickness per AS/NZS 4766, bunding and venting requirements, and produce a design output for sign-off before fabrication starts. If the duty is beyond plastic, we tell you and point you to the right metal fabricator. Brisbane workshop, 1971. DVS 2207 qualified welders. Documented test records survive the project.
Where plastic ends and metal begins
We would rather tell you the truth than sell you the wrong tank. PVDF is not suitable for oleum (fuming sulfuric), and concentrated 98% sulfuric at anything above modest temperature is properly a carbon steel or alloy duty, not a thermoplastic one. Near-anhydrous sulfuric passivates carbon steel by forming a protective ferrous-sulfate film, which is why bulk 93 to 98% acid the world over is stored in steel, with dry-air or desiccant vents to keep moisture out of the head space.
So our honest position on the concentrated end:
- Cool, well-vented 98% in a plastic tank, we will engineer it in PVDF where the temperature genuinely stays low, and we will show you the data behind the selection.
- Hot 98%, oleum, or anywhere the numbers say plastic is marginal, we will say so, and connect you with carbon steel and alloy fabricators we work alongside. You still get the engineering check; you just get the right vessel.
Either way, the design output is honest. We do not quote a plastic tank into a duty it cannot survive.
Where we add value across a sulfuric system
Even when the primary storage vessel is steel, most of the surrounding plastic scope is squarely ours:
- Secondary containment, HDPE bunds and bund liners are well-proven for 98% sulfuric, where exposure is incidental and short-term. Sized to AS 1940 / AS/NZS 4766 minimum, with leak-tested floor seams.
- Dilution and dosing downstream, once concentrated acid is let down to dosing strength (typically ≤50%), the day tanks, dosing skids and pump platforms are back in HDPE’s comfort zone.
- Pipework, vents and fill points, PVC-U suits ambient sulfuric service and many pipe charts rate it to high concentration cold; PVDF gives margin as concentration and temperature climb.
Common configurations
- Bulk storage, 5,000 to 50,000 L+. Tanker top-fill with manway, bottom drain, level instrumentation, vented to atmosphere or scrubbed.
- Day tanks & dosing, 200 to 5,000 L. Calibrated, level-indicated, pump-mount platforms compatible with diaphragm and peristaltic dosing pumps.
- Bunded & secondary containment, primary tank inside an HDPE bund sized to AS 1940 / AS/NZS 4766 minimum. Leak-tested floor seams.
- Vented & scrubbed, vent stacks sized to maximum fill rate. Scrubbing where off-gas is hazardous. Designed against the failure case, not just the operating case.
Standards and compliance
- AS/NZS 4766, wall thickness, weld testing and pressure testing per the Australian standard for plastic chemical storage.
- AS 1940, bunding and venting requirements where applicable.
- DVS 2205 (tank design) and DVS 2207 (welding), welder qualification across HDPE butt welding and extrusion welding. More on DVS 2207.
- ISO 9001:2015, quality management system certified by SGS.
How we work
The same five step process on every job, from first contact to delivered fabrication.
- Brief and specifications review. Send drawings, specs, an SDS or a written description of the duty. An engineer reviews every enquiry. Site visits by arrangement on confirmed projects.
- Engineering design. Material selection, wall thickness calculations, CAD fabrication drawings, weld plan and inspection and test plan. You sign off the design output before fabrication starts.
- Material procurement. Certified plastic stock, traceable to mill certificates where required.
- Fabrication. Brisbane workshop under ISO 9001 control. Welders qualified to DVS 2207, in-process inspection, pressure or leak testing as applicable.
- Delivery and documentation. Crated, palletised or oversize transport Australia-wide, with on-site fit-up where scope requires. Material certificates, weld records and test results are handed over with the job.
Full detail, including what we need from you to quote and what you receive at handover: How we work
Talk to an expert
Considering a rotomoulded alternative? Read why sulfuric acid service rules out rotomoulded, our full engineer-grade comparison.
Frequently asked questions
HDPE handles dilute sulfuric under about 50 percent at ambient. PVC-U suits cool indoor dilute to moderate duties. PP-H extends into the 50 to 70 percent range common in mining. PVDF covers high concentrations at ambient and cool temperatures.
Only cool, well vented 98 percent duty, engineered in PVDF where the temperature genuinely stays low, with the selection data shown. Hot 98 percent and oleum are carbon steel or alloy duties, and we will say so.
The same material that handles 32 percent sulfuric at 25 degrees without complaint will char and stress crack in months at 78 percent or at 60 degrees. Concentration and temperature together drive the selection.
We tell you plainly and connect you with the carbon steel and alloy fabricators we work alongside. You still get the engineering check.
The SDS, concentration, operating temperature, fill cycle and service life. You sign off the design output before fabrication starts.
Trusted across the industries we serve
Get an engineered quote
Send drawings, a sketch, or a description of the duty. An engineer reviews every enquiry and confirms receipt within one business day.