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Machining of fittings

ARRI Machining closely aligns the valve market with the pipe and fittings market. We specialise in the machining of valves and the machining of high-specification fittings.

Fittings and their specifications

At ARRI machining, we have a very suitable technology to solve the problem of machining pipes and fittings: Trevisan Turning Centres.

ARRI utilises the Modular Clamping Systems of the Trevisan machines to achieve an exceptional ability to clamp all parts with unique geometries, carrying out pipes and fittings in cases with high specifications for welding ends or flanges. 

  • The dimensions and geometries of these parts can cover a wide range of sizes and shapes, with machine dimensions from 3" to 84".
  • The designs, based on the needs of each application, can be diverse: Elbows 45º, 60º, 90º, U-s, T-s, reductions.
  • Thicknesses can vary if the application requires low pressures or high pressures. The type of material used can also vary.

Example of machining 

In the following video, we have the example of the machining of a multi-connection weld fitting:

Initial machining: Operators use machine tools, such as lathes, milling machines, or CNC machines, to shape the multi-connection fitting. They create the necessary holes and connections for each pipeline.

Turning, milling or drilling operations: Depending on the specific design, turning operations may be required to shape the fittings and drilling to create the holes for the pipelines.

Welding and assembly: Qualified welders perform welding operations to join the fitting parts. They typically carry out the welding at the plant to utilise the fitting.

Finishing and quality control: Finishing operations are performed by technicians to smooth surfaces, and inspectors carry out testing and quality control to ensure that dimensions, connections, and fitting integrity meet the required standards.


Classification of fittings 

The oil and gas industry employs a diverse range of fittings and accessories to connect, regulate, and direct the flow of fluids within piping systems. Among the commonly used fittings in this industry are:

  • Weld fittings include elbows, tees, reducers and weld-on caps joined to pipelines by welding.
  • Threaded fittings: These include elbows, unions, plugs and other connections that are threaded directly into pipes, making them easy to install and remove.
  • Flange fittings: Flanges connect pipes, including elbows, tees, reducers and plugs that are joined through bolted or welded flanges.
  • Compression fittings: These fittings use rings or nuts to compress the pipe over a conical surface, creating a solid seal.
  • Mechanical joint fittings: These fittings use clamps or mechanical joints to connect two pipes, avoiding welding or threading.
  • High-pressure and high-temperature fittings: Engineers design high-pressure and high-temperature fittings to withstand the extreme pressure and temperature conditions common in oil and gas applications.
  • Gaskets and seals: Fundamental elements to ensure tightness and prevent leakage in connections between fittings and pipes.

The choice of fitting type depends on several factors, including the properties of the fluid being conveyed, pressure, temperature, installation location, and other application-specific requirements. When selecting fittings for oil and gas installations, it is crucial to ensure that they comply with the applicable regulations and safety standards to safeguard the integrity and reliability of these installations.

All these developments are always focused on satisfying the needs of our customers, our reason for being.

At ARRI Machining, we are proud to have more than 30 years of experience being your partner in the machining of valves and fittings.

Contact us to find out how we can collaborate on your projects, ensuring quality, integrity and compliance with the standards required for your machining.