Reliability, durability and operational continuity are essential requirements for industrial plants working in contact with seawater, saline solutions and aggressive chemical substances.
In all these contexts MONEL is widely used. It is a family of alloys made of copper and nickel with a good resistance to corrosion and interesting mechanical properties.
There are different kinds, but the most used is MONEL 400 usually identified as UNS N04400. As already said, the alloy mainly consists of nickel (from 63% to 70%) and copper (from 28% to 34%) besides some other substances in small quantities.
Thanks to the presence of these two chemical elements,it is particularly suitable for saline and highly aggressive contexts in the oil&gas field, in the chemical and petrochemical industry, in plant engineering and naval engineering.
There is also the K-500 monel option that is different from the monel 400 because aluminium and titanium have been added to give it a higher mechanical resistance and more hardness.
Properties
What distinguishes monel from another materials is:
- The corrosion resistance, especially in non-highly oxidizing conditions. It has also to be underlined also a good level of resistance to stress corrosion that often occurs when a material is exposed at the same time both to mechanical stress and to a corrosive environment. Nevertheless, corrosion can not me assumed as absolute. In fact, localized corrosion phenomena can occur in the presence of stagnant water, deposits, crevices or specific operating conditions.
- Workability and welding giving the possibility to realize different kinds of components according to the plant requirements.
- Mechanical resistance, ductility and toughness.
- Low temperature resistance, an important characteristic that makes monel reliable also for a wide temperature range.
All these properties can reduce components deterioration and improve plant reliability over time.
Despite the highly performant characteristics, it is always suggested to make a preliminar technical evaluation since factors such as the temperature, a substances different concentration, the fluid speed, the ventilation and the pollutants presence can influence the material behaviour.
Let analyze more deeply the two main contexts in which it is used.
Marine environment
When operating in the marine environment, due to the presence of chlorides, different levels of oxygenation, temperature fluctuations and the continuous movement of the fluid, it is necessary to select steel materials able to support different corrosive phenomena.
In such context, monel could be the solution.
Among the applications for which this alloy could be used, you can find:
- Heat exchangers and condensers where material compatibility with the cooling fluid must be assessed.
- Pumps, valves and fittings in fluids movement and control systems.
- Shipyard and offshore systems.
- Industrial water treatment systems when the chemical and operating conditions comply with the alloy.
- Desalinization plant.
Chemical and petrochemical industry
Besides marine applications, monel is also used in the chemical and petrochemical industry operating with highly aggressive and corrosive substances.
In this regard, the alloy has a good resistance to acids and, in particular, to hydrofluoric, hydrochloric, and sulfuric acid rather than to alkaline and saline solutions.
Nevertheless, also in this case, it is important to check the real compliance considering potential substances mixture, pollutants and operating conditions changes. Monel, in fact, is not resistant to all the acids. Highly oxidizing contexts, some temperature conditions, the fluid concentration and composition may compromise the performance.
Regarding the applications, in chemical and petrochemical contexts, monel is used for:
- Chemical processing and treatment equipment.
- Heat exchangers and condensers.
- Pipes and components used for compatible fluids handling.
- Hydrocarbon treatment plants.
As already said, a preliminar evaluation can help identify the proper material on the basis of the real technical criteria avoiding the assumption that an alloy is suitable for any corrosive environment. For example, compared to the superduplex material, monel is of course more expensive, but it has got a lower mechanical resistance.
Tecra proposal
Besides the traditional material, in particular AISI 316L, Tecra supply also monel on demand together with other nickel alloys such as Hastelloy and Inconel and with special materials such as Duplex and Superduplex.
Our wide range allow us toevaluate different materials depending on the project requirements and the operating conditions with reference to the chemical, petrochemical, energy and oil&gas field.
If you are looking for monel 400 tubes, visit the website section or contact our commercial office to receive a personalized quotation or simply information.