System for Sodium Hydroxide storage and dilution

When we design our system, we meet all the following conditions:

  • Tanks, pipes and hoses are doubled walled and equipped with leak sensors/alarms
  • Insulated chemical mixing tank designed for the Norwegian cold climate.
  • Fluid filled heating coils made from acid-resistant steel with very large coil surfaces
  • System for sulphuric acid dosing for pH correction
  • Fully automatic liquid-based dilution units for 50 % Sodium Hydroxide equipped with a dosing system. The systems are supplied with liquid containment, leak detection and heating elements.
  • Custom size solutions, including 5000-gallon chemical storage tank
  • Satisfy the provisions of the “Tank regulations” regarding safety barriers required by law
  • Sulphuric acid dosing tank that adds benefit of lowering total alkalinity

Sodium Hydroxide (NaOH) in concentrated form is an extremely strong alkaline liquid. For this reason, Sodium Hydroxide must be stored and handled with great care. Sodium Hydroxide is delivered in solid form as pellets, or in liquid form. Dissolving pellets in water requires a separate mixing plant. From an HSE perspective, such mixing plants are not an optimal solution.

Sodium Hydroxide in liquid form is delivered in two concentrations: 50 % or 30 % (known as winter Sodium Hydroxide). As the 50 % concentration crystallises at 12˚C , it can create problems if the system is not designed properly. Crystallisation in tanks, pipes, pumps and other equipment has the potential to block the entire system. Consequently, for much of the year the liquid must be heated. Storage tanks must be well insulated to keep heat loss to a minimum. It is worth noting that what a purchase of lye with a concentration of 30 %, this will be avoided. However, your transport costs will increase dramatically. In the long run, opting for the lower concentration will be less environmentally friendly and more expensive.

The heating elements that are in contact with the Sodium Hydroxide should be designed to prevent the Sodium Hydroxide from “combusting”. Such combustion would have an insulating effect. It would lead to reduced efficiency of the heating elements and in turn to increased power consumption. In the worst-case scenario, the Sodium Hydroxide can crystallize if the temperature becomes too low. It is important that the heating element has a relatively large surface area.

Sodium Hydroxide is covered by Section 18 of the Pollution regulations (also referred to as the “Tank regulations”), which involves meeting certain requirements during storage and internal distribution.

Our solutions can help to prevent problems with acidic water in fish tank to make sure that the fish has optimal environment for its growth. That way acidic fish tank will not interrupt important life processes on your fish farm.


When we choose a supplier of new systems for storage and dilution of Sodium Hydroxide for our customers, ArcticFlow was the only company able to offer a complete system that meets our requirements for a safe and good solution for receiving, storing, diluting and internal transport of Sodium Hydroxide.

Steinar Eriksen

Norsk Lut AS