Malleable iron is a type of cast iron that has undergone a unique heat treatment process called annealing. This process makes it less brittle and more ductile than regular cast iron, allowing it to be shaped and molded into various forms. This improved flexibility is what makes malleable iron ideal for pipe fittings. Annealing is the key step in making malleable iron. The castings are heated to a specific temperature and held there for a set period. This process transforms the cast iron’s microstructure, making it more pliable.
Malleable iron creates threaded pipe fittings, elbows, tees, couplings, unions, bushings, crosses, and more. These fittings can be easily screwed onto pipes without welding, making installation and modification more convenient. Threaded fittings are used in applications where the pipes must be easily disassembled and reassembled. This versatility allows it to be used in complex piping systems requiring different fittings. Malleable iron is relatively corrosion-resistant compared to other materials like plain cast iron. This makes it suitable for applications where exposure to moisture or corrosive substances is a concern. However, it is less corrosion-resistant than materials like stainless steel.
This material is also known for its high-temperature resistance, making it suitable for hot water, steam, and heating systems applications. Malleable iron fittings are popular because of their strength and durability, which is important in applications where the pipes may be subjected to high pressure, mechanical stress, or heavy loads.
It’s important to note that while malleable iron has many advantages, it also has limitations, such as lower corrosion resistance than materials like stainless steel or brass. Therefore, the choice of material for pipe fittings should consider the application’s specific requirements and the potential for exposure to corrosive environments.