Monel Alloy and Monel Valves Introduction
Monel Alloy Summary:
Monel is a group of nickel alloys, primarily composed of nickel (from 52 to 67%) and copper, with small amounts of iron, manganese, carbon, and silicon. Alloys with copper contents 60% or more are called cupronickel. Stronger than pure nickel, Monel alloys are resistant to corrosion by many aggressive agents, including rapidly flowing seawater. They can be fabricated readily by hot- and cold-working, machining, and welding.
Titanium Alloy Futures:
- high corrosion resistance to acids and alkalis.
- resistance to alkalis.
- good ductility (easy to shape and form)
- ease of welding, brazing, and soldering
- high mechanical strength
- availability in different forms like sheets, plates, rods, bars, pipes, and tubes
- attractive appearance and finishes.
- ability to hold up in high-temperature situations as well as low temperatures
Monel Alloy Valve Applications:
Monel valve refers to both the body and trims(internal parts) of the valve are made of Monel alloys. It is widely used for the alkylation device of the hydrofluoric acid(HF) regeneration column in an oil refinery. Considering the high temperature and high moisture contained, fully Monel valves shall be utilized. Besides, this type of valve can also be used in high-concentration chlor alkaline solution systems. Another type is valves with CS/SS body and Monel trims: in the low-temperature section of a HF acid system, since the carbon steel can withstand anhydrous HF acid at temperatures below 71°C, it is widely selected as the valve body material. However, the valve trim materials shall be Monel alloys to meet the corrosion and erosion resistance requirement within the body cavity. In applications involving ethylene, propylene, liquid oxygen, pure oxygen, and seawater, usually, valves with SS body and Monel trims are chosen. The combination of CS/SS and Monel in valve manufacture may significantly reduce the production cost.
Monel Alloy Material Grades:
| Monel Grade/Trade Name |
ASTM/AISI Alloy Type |
UNS No. |
%Ni |
%Cu |
%Fe |
%Mn |
%Al |
%Ti |
%Si |
| Monel 400 |
B 127/ B 164 |
N04400 |
Min. 63 |
28-34 |
Max 2.5 |
Max 2.0 |
|
|
Max 0.5 |
| Monel 401 |
|
N04401 |
Min. 63 |
28-34 |
Max 2.5 |
Max 2.0 |
|
|
Max 0.5 |
| Monel 404 |
|
N04404 |
52-57 |
Remaining |
Max 0.5 |
Max 0.1 |
Max 0.05 |
|
Max 0.1 |
| Monel 405 |
B 164 |
N04405 |
Min. 63 |
28-34 |
Max 2.5 |
Max 2.0 |
|
|
Max 0.5 |
| Monel K500 |
B 865 |
N05500 |
Min. 63 |
27-33 |
Max 2.0 |
Max 1.5 |
2.3-3.15 |
0.35-0.85 |
Max 0.5 |