Secondary wall required · material chosen by acid

Design and fabrication of
acid storage tanks resistant to corrosion!

The shell material must match the exact acid, not be chosen in general

Different acids behave very differently towards metals. Concentrated sulphuric acid at ambient temperature is fairly compatible with carbon steel, but the same acid at a lower concentration or a higher temperature can quickly corrode that same metal. That is why an 'acid tank' is not a single product: each design depends on the acid, its concentration and its temperature.

Acid storage tank built by Behineh Ab
Shell material
316L stainless, lined carbon steel or FRP
Internal lining
Rubber, acid-resistant epoxy or FRP
Secondary wall
At least the volume of the main tank
Venting
Vent resistant to acid vapours

Key features

Material chosen precisely for the acid and its concentration
Rubber or FRP lining for hot, concentrated acids
Secondary wall required to contain leaks
Venting designed to resist acid vapours
Emergency shower and eyewash at the installation site
Leak test and weld quality control before delivery
Acid storage tank with an FRP internal lining

Technical details

Thanks to its molybdenum content, 316L stainless steel resists chloride and dilute acids better than 304; but for hot, concentrated acids such as hydrochloric acid, a rubber lining or FRP (fibreglass) is usually the safer choice.

Before choosing the material, Behineh Ab checks the concentration, temperature and possible impurities of the project's acid, then designs and builds the tank together with a secondary wall and the necessary safety equipment.

Technical specifications

Shell material
316L stainless, lined carbon steel or FRP
Internal lining
Rubber, acid-resistant epoxy or FRP
Secondary wall
At least the volume of the main tank
Venting
Vent resistant to acid vapours
Safety equipment
Emergency shower and eyewash on site

Which acid suits which shell material?

Before choosing the material, establish which family the acid belongs to: strong mineral acids (sulphuric, nitric, phosphoric) behave differently from halogen acids (hydrochloric, hydrofluoric). The table below is a first guide.

Acid
Recommended material
Main limitation
Concentrated sulphuric (cold)
Carbon steel
Unsuitable when dilute or hot
Dilute sulphuric
316L stainless or FRP
Temperature and flow velocity must be checked
Hydrochloric (any concentration)
FRP or rubber lining
Ordinary metals corrode quickly
Concentrated nitric
Stainless steel (304/316L)
Dilute concentrations need closer review
Phosphoric
316L stainless or FRP
Fluoride impurities reduce resistance
Which acid suits which shell material?

Polyethylene (HDPE): the most common practical choice

Alongside stainless steel and FRP, which are recommended for hot, concentrated acids, a large share of acid tanks are in practice made of high-density polyethylene or fibreglass-reinforced polyethylene — especially for phosphoric acid (odourless, widely used in fertiliser and beverage production) and peracetic acid (a sanitiser in the food and pharmaceutical industries), which are well compatible with HDPE at normal concentrations.

Before buying a polyethylene acid tank, check the exact name and concentration of the chemical; polyethylene's resistance changes sharply with concentration and temperature, and the compatibility of fittings, gaskets and valves with that chemical must be confirmed separately.

Required secondary wall and safety equipment

Unlike many other chemicals, an acid leak is a direct danger to people, so a secondary wall is not optional for acid tanks but a practical requirement. The containment basin must be able to hold the whole tank volume in a worst-case leak.

Alongside the secondary wall, an emergency shower and eyewash close to the tank, and auxiliary equipment (valves, fittings, pumps) made of materials compatible with the same acid, are an inseparable part of a safe design.

Periodic maintenance and inspection of acid tanks

Even with the right material, periodic thickness inspection of the shell (especially at welds and the tank bottom) is essential to spot local corrosion early. Thinning in acid tanks is usually uneven and happens faster where there is turbulence or vapour condensation.

Rubber or FRP internal linings also have a limited life and must be inspected at intervals set by the manufacturer and replaced when needed, so the acid never reaches the base metal.

Applications and industries

Metal plating and finishing
Metal plating and finishing
Industrial water and wastewater treatment
Industrial water and wastewater treatment
Petrochemical and chemical industries
Petrochemical and chemical industries
Chemical fertiliser plants
Chemical fertiliser plants
Textile and dyeing industries
Textile and dyeing industries
Industrial laboratories
Industrial laboratories

Frequently asked questions

Request a quote
Acid storage tank fabrication

Enter the pressure, temperature and fluid; our engineers send a technical proposal and price within 24 working hours.

  • Written technical reply with a proposed concept drawing
  • Site visit in Tehran and surroundings
  • 24-month warranty on fabrication and welding
Call our engineering office
+98 21 4686 6276

Your details are confidential and used only to prepare a technical proposal.

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