AIR COMPRESSOR
& PIPES LEADER
& PIPES LEADER
2th Jun, 2026
Discover the 4 common methods of installing compressed air piping: threaded, flanged, welded, and socket joints. Learn how to choose the right connection for your system.
Compressed air piping can be connected using a variety of methods, including threaded, flanged, welded and socket joints. When selecting a connection method for compressed air piping, factors such as pipe pressure, medium characteristics, installation conditions and cost must be taken into account. For high-pressure, large-diameter pipes, welded and flanged connections may be the better choice; whereas for low-pressure, small-diameter pipes, threaded and socket connections may offer greater advantages. In practical applications, engineers and designers should select the appropriate connection method based on specific circumstances to ensure the safe, stable and efficient operation of the piping system. The following is an introduction to several commonly used connection methods:
1. Threaded connections: Threaded connections are a simple and straightforward method of joining pipes, involving the machining of threads at the pipe ends, followed by tightening with nuts and washers. This connection method is suitable for low-pressure, small-diameter compressed air pipes. The advantages lie in its ease of installation and disassembly, as well as its good sealing performance.
2. Flanged connections: Flanged connections involve joining two pipes together using flanges and bolts. They are characterised by high connection strength, good sealing performance and strong adaptability, making them suitable for compressed air piping systems with various pressure, temperature and medium characteristics. Furthermore, flanged connections facilitate installation, disassembly and maintenance. However, they are relatively more expensive and require a certain amount of installation space.
3. Welded connections: Welded connections involve joining two pipes by melting the pipe material. This method offers high connection strength, excellent sealing performance and a long service life, making it suitable for high-pressure, large-diameter compressed air pipelines. Furthermore, welded connections are space-saving and aesthetically pleasing. However, they require a high level of technical expertise during installation; any issues with weld quality may lead to serious consequences.
| Connection Method | Suitable Pipe Materials | Recommended Pressure Range | Cost (Material + Labor) | Installation Difficulty | Lifespan & Maintenance | Ideal Applications |
|---|---|---|---|---|---|---|
| Threaded | Galvanized Steel, Carbon Steel, Plastic (limited) | Low to Medium (Up to 15 bar / 217 PSI) | Low (Cheap fittings, low labor cost) | Easy (Requires basic threading tools) | Medium (Prone to air leaks over time due to vibration) | Small workshops, terminal branch lines, temporary setups. |
| Flanged | Carbon Steel, Stainless Steel, Large-diameter Pipes | Medium to High (Up to 40+ bar / 580+ PSI) | High (Expensive flanges/bolts, high labor) | Medium (Requires alignment and torque control) | Long (Easy to disassemble and replace gaskets) | Main distribution lines, connection to air compressors/dryers, large industrial plants. |
| Welded | Carbon Steel, Stainless Steel | Very High (100+ bar / 1450+ PSI possible) | High (Labor) (Low material cost, but requires certified welders) | Hard (Requires professional welding skills & safety permits) | Excellent (Permanent, zero-leakage, asset lifespan) | Heavy industries, high-pressure systems, permanent main headers where leaks cannot be tolerated. |
| Socket-and-Spigot / Push-In | Aluminum alloy pipes, Stainless steel pipes, Plastic | Low to Medium-High (Up to 16 bar / 232 PSI) | Medium-High (Material) (Higher fitting cost, but ultra-low labor cost) | Very Easy (Fast push-to-connect or press-fit, no special skills) | Long (O-ring sealed, corrosion-free, easy to modify) | Modern modular factories, electronics cleanrooms, automotive assembly lines using aluminum piping. |
4. Socket-and-Spigot / Push-In Connections: This method involves interlocking the socket and spigot at the pipe ends, followed by sealing with a sealing material. This connection method is suitable for low-pressure, small-diameter compressed air pipelines. Socket-and-spigot connections offer advantages such as simple installation and good sealing performance. However, as pipeline pressure and diameter increase, the sealing performance and stability of socket-and-spigot connections may be compromised.
