Material is the decision that matters
Most chemical tank failures trace back to one choice made at enquiry stage: the shell material. The right answer depends on the product, its concentration, its temperature and its chloride content — so we start every enquiry there, not with a price per tonne. The table below is our starting guidance; the final selection is confirmed against your process data.
| Material | Specification | Typical chemical service |
|---|---|---|
| Stainless steel 304 / 304L | SA 240 | Demineralised water, food-grade products, mild chemicals |
| Stainless steel 316 / 316L | SA 240 | Phosphoric acid, pharmaceutical intermediates, sea water |
| Duplex 2205 / super duplex 2507 | SA 240, UNS S31803 / S32750 | Aggressive chlorides, brackish water, urea |
| Rubber-lined carbon steel | SA 516 + Hypalon, butyl or neoprene | Hydrochloric acid, dilute sulphuric acid |
| FRP-lined carbon steel | SA 516 + glass-fibre vinyl ester | Concentrated acids, alkalis, solvents |
Getting the material right is only half of it. Stainless and duplex lose their corrosion resistance if they are welded carelessly, so tank welding follows the same controls as our duplex and stainless fabrication work — controlled heat input, ferrite verification on duplex, and PMI traceability on every plate.
Reference: phosphoric acid storage tank, Jhabua
For Krishna Phoschem Ltd. at Jhabua, Madhya Pradesh, HAIL delivered a large-diameter phosphoric acid storage tank — 19.5 m diameter × 12.6 m high — on a turnkey basis: RCC tank pad foundation and miscellaneous civil works, detailed engineering, fabrication, erection and welding, with the complete structural and civil scope under one contract.
Tank types for chemical service
- Vertical atmospheric tanks to API 650 and IS 803 — the bulk of chemical storage, cone or dome roof.
- Low-pressure tanks to API 620 where the product needs a small positive pressure or vapour containment.
- Pressure storage to ASME Section VIII, built under the workshop’s ASME U-Stamp and licensed under PESO SMPV(U) where it applies.
- Refrigerated and double-wall tanks for ammonia and other liquefied gases — see cryogenic tank construction.
Shop-built or field-erected
Large-diameter tanks are erected on your site: shell plates are cut, bevelled and rolled at our Kalol workshop near Vadodara — which rolls plate up to 50 mm thick and 3 m wide — then erected by jacking. Smaller tanks and pressure storage can be built complete in the workshop and despatched. Send the size and we will tell you which route is cheaper for your job; it is usually decided by transport limits, not by preference.
Turnkey, from foundation to handover
One contract covers what is usually split between three contractors: the tank pad or ring-wall foundation, the tank itself, and the testing. Welders and procedures are qualified to ASME Section IX; vertical shell seams are radiographed by an approved NDT agency, bottom welds are vacuum-box tested, and every tank is hydrotested with a phased settlement survey before handover. Third-party inspection by Lloyd’s, BV, TÜV, RINA or IBR is accepted.
Storing petroleum products rather than chemicals? See our crude oil and petroleum storage tank and diesel and fuel storage tank pages.
Frequently asked questions — chemical storage tanks
Which material is right for my chemical storage tank?
It depends on the product, concentration, temperature and chloride content. As a starting point: SS 316/316L for phosphoric acid and pharmaceutical intermediates; duplex for aggressive chlorides; rubber-lined carbon steel for hydrochloric and dilute sulphuric acid; FRP-lined carbon steel for concentrated acids, alkalis and solvents. We confirm the final choice against your process data.
Have you built a large chemical storage tank?
Yes — a 19.5 m diameter × 12.6 m high phosphoric acid storage tank for Krishna Phoschem Ltd. at Jhabua, Madhya Pradesh, delivered turnkey from the RCC tank pad foundation through engineering, fabrication, erection and welding.
Which standards do you build chemical tanks to?
API 650 and IS 803 for vertical atmospheric tanks, API 620 for low-pressure tanks, and ASME Section VIII for pressure storage, built under our ASME U-Stamp with PESO SMPV(U) licensing where it applies.
Do you include the foundation?
Yes. We deliver chemical tanks turnkey, including the RCC tank pad or ring-wall foundation, so foundation and tank are designed and built under one contract.
Can a chemical tank be built in your workshop and delivered?
Smaller tanks and pressure storage can be built complete at our Kalol workshop and despatched; large-diameter tanks are erected on site from shell plates rolled in the workshop. Send the size and we will recommend the cheaper route.
How are the welds tested?
Welders and procedures are qualified to ASME Section IX. Vertical shell seams are radiographed by an approved NDT agency, bottom welds are vacuum-box tested, and every tank is hydrotested with a phased settlement survey.