Learn about our risk-reducing nitric acid range.
Start by selecting the right grade
Your customer may have already specified ASTM 304L tube for a new plant. However, they may also be asking for your guidance on materials selection. The truth is that while ASTM 304L is good for many parts of the plant, it will reach its limits in boiling nitric acid in heat exchangers – shortening service life. You may want to advise them to move up to Alleima® 2RE10, a more corrosion-resistant tube with higher chrome content. In the Huey test result shown below, several tube grades were placed in boiling nitric acid at 65% for 5 x 48 hours with service conditions similar to a nitric acid condenser. As shown, the corrosion rate was dramatically lower.
The standard that sets the standard
Does your life become easier by just delivering to specifications and standards? Is there more to it? Yes there is. Working with Alleima stainless tube will not only ensure a high quality standard, but streamline your fabrication process. You can work quickly and confidently with the knowledge that you’ve got a material at the top of all parameters within a standard – from ovality, roundness, cleanliness and consistency to wall thickness, chemical composition and welding consumables. Finally, you gain access to our in-depth R&D knowledge, with some 2700 experts.
Welding
For decades, our tube material experts have worked closely with our welding R&D team to innovate the perfect welding consumables. We can even offer advice on the settings of the welding machine itself. Please contact us for more information.
Our knowledge is your competitive advantage
As you work with our tubing materials, you may have questions. So you’ll be happy to know that Alleima has one of the largest and most extensive materials R&D organizations within its field, ready to assist and support. Because you have access to this knowledge when working with us, you don’t need to have your own in-house team. Together we can specify, test and develop the best methods of fabricating, regardless whether you’re focused on welding, bending or analyzing.
The perfect range
For more than 60 years, we’ve contributed to the nitric acid and UREA industries with premium materials and support. Together we have developed and been part of fine-tuning the industry to where it is today. A long track record has built our industry knowledge, and today we have a carefully tailored range of materials and dimensions to meet the production challenges of nitric acid production.
Alleima® 2RE10 (UNS S31002) – The optimal risk reducer for nitric acid production
Chemical composition (nominal), %
| C | Si | Mn | P | S | Cr | Ni | Mo |
|---|---|---|---|---|---|---|---|
| ≤0.015 | ≤0.15 | 1.8 | ≤0.020 | ≤0.005 | 24.5 | 20 | ≤0.1 |
Developed specifically for demanding applications in the nitric acid industry, Alleima 2RE10 is gaining a reputation for its ability to resist corrosion at higher temperatures, enabling process equipment to last longer. It is especially well suited for the tubing used in condenser-coolers where re-boiling can accelerate corrosion rates. With 24.5% chromium and 20% nickel, it is highly resistant to corrosion as well as having extremely low carbon and impurity levels. Available in outer diameters up to 80 mm (3.15 in).
Key benefits
- Extremely low carbon and impurity levels
- Excellent resistance to corrosion in nitric coolers/condensers
- Excellent resistance to intergranular corrosion
- Good resistance to pitting
- Good weldability
- Very high consistency and tight tolerances
Alleima®3R12 (UNS S32304) – The all-round risk reducer for nitric acid plants
Chemical composition (nominal), %
| C | Si | Mn | P | S | Cr | Ni |
|---|---|---|---|---|---|---|
| ≤0.030 | 0.5 | 1.3 | ≤0.030 | ≤0.015 | 18.5 | 10 |
Alleima® 3R12 (ASTM 304L) is our most widely used grade for nitric acid facilities, capable of handling nitric acid over a wide range of temperatures and concentrations up to about 60% at the atmospheric boiling point. Being a versatile austenitic chromium-nickel steel, it can handle most of the wet corrosion problems appearing after the ammonia converter. However, under certain conditions, such as higher temperatures, or higher chloride or acid concentrations, a higher alloyed grade is recommended. Tube is stocked in various sizes in the solution annealed and white pickled condition.
Key benefits
- Resistant to general corrosion (oxidizing nitric acid)
- Improved machinability
Alleima® SAF 2304 (UNS S32304) – For higher strength and risk reduction in nitric acid production.
Chemical composition (nominal) %
| C | Si | Mn | P | S | Cr | Ni | Mo | Cu | N |
|---|---|---|---|---|---|---|---|---|---|
| ≤0.030 | ≤1.0 | ≤2.0 | ≤0.035 | ≤0.015 | 22.5 | 4.5 | 0.3 | 0.3 | 0.1 |
This lean duplex (austenitic-ferritic) stainless steel offers very good resistance to stress corrosion cracking (SCC) and favorable resistance to general corrosion and pitting. As a duplex steel, it also offers very high mechanical strength - roughly double the yield strength of ASTM 304L steels. The high mechanical strength allows for lighter constructions, more compact system designs and less welding.
Key benefits
- Very good resistance to stress corrosion cracking
- Good resistance to general corrosion
- Double the yield strength of ASTM 304L
- Design advantages due to mechanical properties