Tube Fittings

General information on tube fittings

Tube fittings are tube accessories with which pipelines and components installed in piping systems can be connected tightly. Even after installation, this connection remains detachable. Tube fittings are available in many different designs for a wide range of applications. Requirements for tube fittings are specified, among other things, in EN 10226-1 (tube threads for thread-sealing connections, Part 1: Tapered external threads and cylindrical internal threads).

What types of tube fittings are available?

There are several types of pipe fittings available, including:

• Elbows are used to change the direction of flow in a piping system. They are available in various angles, such as 45 degrees, 90 degrees, and 180 degrees.
• Tees are fittings that split the flow of a fluid into two directions. They have three openings, with one on the top and two on the bottom.
• Reducers are fittings used to connect pipes of different sizes. They are available in concentric and eccentric types.
• Caps are fittings used to close the end of a pipe. They are available in various sizes to fit different pipe diameters.
• Flanges are fittings used to connect pipes to other pipes, valves, or equipment. They are available in various sizes and pressure ratings.
• Unions are fittings used to connect pipes that can be easily disassembled for maintenance or repair. They have two female ends that can be joined together using a male end.
• Couplings are fittings used to connect two pipes or a pipe to a fitting. They are available in various sizes and types, such as full couplings, half couplings, and reducing couplings.
• Adapters are fittings used to connect pipes or fittings with different sizes or types. They are available in various sizes and shapes, such as male-to-female, female-to-male, and male-to-male.

How are tube fittings made?

Tube fittings are often made of stainless steel or brass, gunmetal or malleable cast iron. The most important manufacturing processes are turning, drop forging and casting. In turning, the components are manufactured from pre-material in bar or tube form on automatic lathes by machining. For drop forging, a heated blank is placed in the bottom die and the top die strikes the forging to shape it into the desired forging. Casting creates a solid from liquid material in a mould. This process is very suitable for the mass production of components with complex shapes. Thin-walled castings can be made well from malleable cast iron, an iron-carbon-silicon alloy that is easy to cast, tough and has high strength. After casting, malleable cast iron is initially hard and brittle. Through a heat treatment, annealing, the mechanical properties, toughness and machinability improve greatly.

Application areas of tube fittings

Tube fittings are very versatile and are used in these areas, for example:

• Pipeline construction
• Plant engineering
• Apparatus engineering
• Mechanical engineering
• Vehicle construction
• Shipbuilding
• Building services
• Drinking water and heating installations
• Solar technology

Advantages of tube fittings

With tube fittings, tight connections can be made between pipelines and components installed in piping systems without the use of machines or soldering, and these connections can be detached.

There are several advantages to using tube fittings:

• Versatility: Tube fittings can be used to connect a wide range of tubes and pipes, including those made of different materials, such as steel, brass, copper, and plastic.
• Leak-tight seal: Tube fittings are designed to create a leak-tight seal when connected, ensuring that the fluid or gas being conveyed does not escape.
• Easy installation & modification: Tube fittings can be easily installed, modified, reassembled or disassembled, making them ideal for maintenance and repair. Also they are a flexible choice for piping systems that may need to be modified or expanded in the future.
• Durability: Tube fittings are typically made of strong and durable materials, such as steel or brass, which makes them resistant to corrosion and wear.
• Cost-effective: Tube fittings are typically less expensive than other types of fittings, such as welded fittings, making them a cost-effective choice for many applications.