Standard corrosion rate
Published by Alireza Haghighat Nejad in Technology
Tags
Category: Technology
- Scale & Corrosion
- Corrosion Prevention
- Heat Transfer Fluids
- Gravity-film Heat Exchanger
- Wastewater Heat Recovery
Published by Alireza Haghighat Nejad in Technology
Category: Technology
Dear Alireza, I suggest you to visit this link where you will probably be able to find the answers you are looking for and not only about the corrosion rate for heat exchangers: https://www.corrosionpedia.com/definition/337/corrosion-rate
Obviously, the corrosion rate is always variable and first of all it depends on the kind of material used, its thickness, the temperatures and the fluids used, both on the shell side and inside the tubes themselves.
Published by Duilio Calura, CEO at SCHELL GmbH & Co.KG
A tank wall required a 5 mm wall thickness for mechanical considerations. The designer has determined that the corrosion rate will be 0.4 mm/yr and the expected life of the tank will be 10yr. The total corrosion allowance is the corrosion rate per year (0.4 mm x 10 yr = 4 mm).
The corrosion allowance is doubled to 8 mm as a safety consideration.
Published by redouane bendenni
What you report is a very empirical calculation and not applicable when it concerns the compliance with safety standards.
In fact, the corrosion rate is not linear because it cannot consider the variables that will take place during the lifetime of the structure itself.
Published by Duilio Calura, CEO at SCHELL GmbH & Co.KG
| Corrosion allowance for steel pipes | mm |
| Superheated steam | 0.3 |
| Saturated steam | 0.8 |
| Steam coils in cargo tanks and liquid fuel tanks | 2.0 |
| Feed water for boilers in open circuit systems | 1.5 |
| Feed water for boilers in closed circuit systems | 0.5 |
| Blow-down systems for boilers | 1.5 |
| Compressed air | 1.0 |
| Hydraulic oil | 0.3 |
| Lubricating oil | 0.3 |
| Fuel oil | 1.0 |
| Thermal oil | 1.0 |
| Fresh water | 0.8 |
| Sea water | 3.0 |
| Refrigerants referred to in Section 13 | 0.3 |
| Cargo systems for oil tankers | 2.0 |
| Cargo systems for ships carrying liquefied gases | 0.3 |
Notes..
| Corrosion allowance for non-ferrous metal pipes | mm |
| Copper | 0,8 |
| Brass | 0,8 |
| Copper-tin alloys | 0,8 |
| Copper-nickel alloys with less than 10% of Ni | 0,8 |
| Copper-nickel alloys with at least 10% of Ni | 0,5 |
| Aluminium and aluminium alloys | 0,5 |
Published by redouane bendenni
Thanks so much.
Published by Alireza Haghighat Nejad