Cast iron fittings are components used in plumbing systems to connect, divert, control, or terminate the flow of fluids in cast iron piping systems. Cast iron fittings have been traditionally used in plumbing systems due to their durability, strength, and heat resistance. Here’s an overview of cast iron fittings:

1. Material: Cast iron fittings are typically made from gray cast iron, which is an alloy of iron, carbon, and silicon. This material provides excellent strength, corrosion resistance, and heat resistance, making it suitable for use in plumbing systems handling hot and cold water, sewage, and drainage.

2. Types of Fittings:

   • Couplings: Couplings are used to join two sections of cast iron pipe together. They may be plain-end couplings or hub-and-spigot couplings, depending on the type of connection used in the piping system.

   • Elbows: Elbows are fittings with a 90-degree or 45-degree bend, allowing for changes in direction within the piping system.

   • Tees: Tees have three openings and are used to create branch connections in the piping system.

   • Reducers: Reducers are used to connect pipes of different diameters, allowing for a smooth transition in the flow of fluids.

   • Adapters: Adapters are used to connect cast iron pipes to other types of pipes or fittings, such as PVC, copper, or brass fittings.

   • Caps and Plugs: Caps and plugs are used to seal the end of a cast iron pipe, preventing the flow of fluids.

   • Cleanouts: Cleanouts are fittings with removable covers used to access and clean out debris or blockages from the piping system.

   • Traps and Bends: Traps and bends are fittings used in drainage systems to create traps and prevent the backflow of gases or odors from the sewer system.

3. Sizes: Cast iron fittings are available in a range of sizes to accommodate different pipe diameters and system requirements. Common sizes range from small fittings for residential plumbing applications to larger fittings used in commercial, industrial, and municipal piping systems.

4. Connection Methods: Cast iron fittings are typically joined to cast iron pipes using mechanical methods such as compression gaskets, lead and oakum joints, or threaded connections. These connection methods provide secure and leak-proof joints suitable for various applications.

5. Applications: Cast iron fittings are used in a variety of applications, including residential plumbing, commercial buildings, industrial facilities, and municipal infrastructure. They are commonly used in drainage, sewage, and venting systems, providing durable and reliable solutions for fluid handling and disposal.

Despite the widespread use of modern materials like PVC and ABS in plumbing systems, cast iron fittings continue to be preferred in certain applications where their strength, durability, and fire resistance are valued. However, they may be less common in newer construction projects due to their heavier weight and higher installation costs compared to alternative materials.