Caustic soda is a chemical compound of formula NaOH, also called hydroxide
Of sodium. It is one of the most used chemicals in the laboratory and the environment
For the production of pulp and other chemical products: plastics, textiles
Synthetic products, cleaning products for domestic or industrial use, gasoline production and
Biodiesel, soaps or used in the treatment of water to increase pH and

Neutralize all types of acid water before they are discharged into sewers; The softening of
Drinking water by increasing the pH; Recovery and removal of ion exchangers
Heavy metals are also a food additive (E524).
The danger of sodium hydroxide is corrosion/irritation as soon as its concentration
Exceeds 0.5%.
In order to avoid the phenomenon of cracking resulting from the residual stresses (SCC)
Used NACE-Avoid caustic stress corrosion cracking of refinery equipment and
Piping which ensures satisfactory use of carbon steel in contact with soda ash
The conditions are 50% concentration and 48 ° C.
The material used is carbon steel which gives us the choice: (Table )

Table 18: Choice of piping materials
The diameter of the pipes studied is: 100 mm
The material used is: ASTM A53 Gr. B.
Having a yield strength of min = 241 MPa, and a minimum tensile strength = 414
Before starting to calculate the thickness of the pipes, the designation
Standardized according to the standard shown in the table below:

Table 19: Standard designation
1: Nominal diameter (DN, NPS – Nominal pipe size)
2: The fluid
3: Unit number
4: Serial number of the line
5: Class * of the piping B B 3
with B: Class of Flange 150
      B: Material and the 3: Serial No
6: Insulation code
7: Tracing Code
Class * = The class of piping is a specific standard plug for each fluid
, Which includes materials suitable for the
Piping and equipment, the different diameters, and the type of instruments used.

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