Sodium Hydroxide

Sodium Hydroxide Guidelines

A highly caustic base and alkali which requires special storage consideration.

Sodium hydroxide, also known as lye and caustic soda, is a white solid crystalline that is highly soluble in water. Sodium hydroxide has many uses: water treatment, pulp and paper manufacturing and cleaning agents such as soaps and detergents. When it comes to storing this chemical, the following factors must be considered:

Indoor or outdoor storage.
Maintain Temperature.

While crystallization of the product may not affect the useful life of the tank, it may affect the processing for which it is being used. Sodium hydroxide storage tanks may require the use of insulation and/or heat maintenance on the exterior, to ensure the product does not crystallize.

A fiberglass tank is a great way to store sodium hydroxide but should not be used for diluting.

Product Storage

NaOH

Technical Data

Resin:

Concentration %	Temperature¹	Resin
0.5 – 5	≤ 150° F.	Derakane 411
6 – 25	≤ 120° F.	Derakane 411
26 – 50	≤ 150° F.	Derakane 411

1. Higher temperatures may be allowed, but the service life of the tank will be reduced. See Derakane’s latest Chemical Resistance Guide.

CAUTION! Fiberglass tanks are NOT designed for sodium hydroxide dilution. Dilution of sodium hydroxide will cause an exothermic reaction resulting in temperatures higher than those allowed for fiberglass tanks.

Veil:

Two-ply Nexus® (Synthetic)

Catalyst:

Co/MEKP (Cobalt Octoate / Methyl Ethyl Ketone Peroxide) in the structural layers

Cure:

Hot air post cure after assembly for four hours @ 180˚ F.

Tank Exterior:

If the tank is to be located outdoors:

Each tank has U.V. inhibitor in the exterior resin layer.
Sodium Hydroxide crystallizes at approximately 65° F. The tank may require insulation, as a minimum. However, a tank Heat Maintenance Unit (HMU) may also be required. If the HMU is required, the customer is to specify the Maintain & Outside Ambient temperatures.

Fittings:

Belding Tank uses only Integral (neck and flange face molded together) flanged nozzles.

Bolting Material: T-316 S.S. Standard (Hastelloy-C Optional)

Gasket Material: EPDM Standard

Venting:

Unless otherwise noted, all tanks are designed for atmospheric pressure only.

Belding Tank recommends the vent be equal to or larger than the largest inlet or outlet fitting.

Plumbing to the tank:

Use of flexible connections resistant to sodium hypochlorite –

Allows for lateral and vertical expansion and contraction of the tank
Reduces pump and piping vibration stress on the tank

NOTE: Flexible Connections should be connected to the tank flange. Piping, valves and pumps must have structural support independent of the tank.