Hose, pipes, and tubes are mostly used in the hydraulic industry for pumping hydraulic fluids through the system. Among these, hoses are mostly used because of the flexible structure that enables to reduce the overall size of the system design. But, is it possible to use hydraulic hoses for all your applications? No, the selection is completely dependent on the system requirements and work environment considerations. Pipes are mostly preferred for hydraulic systems that work under extreme pressure and temperature.
Compared with hoses, pipes have a rigid structure and are mostly built with steel, copper, or stainless steel. Welding was a traditional approach used for joining metals and fabricating pipe systems. MIG(metal inert gas) welding, TIG(tungsten inert gas) welding, stick(shielded metal arc welding) welding, and friction welding(solid-state process) are the most common welding procedures used for joining two pipes together. The welding approach was suggested because of the high-pressure requirements in the hydraulic systems. But, incorrect welding can result in serious consequences due to welding defects and residual stresses. Welding defects include incomplete fusion, cracks, cavities, excessive spatter, and lack of penetration and inclusion. As mentioned, distortion and residual stresses are other reasons for welding-related issues that arise when you don’t consider thermal conductivities and expansions of two dissimilar metals upon joining. The recently evolved non-welded piping technology will be is comparatively safe and reliable. More details about this technology are mentioned in this article.
What is non-welded piping technology? Just like the name suggests, the non-welded pipe connections join two hydraulic pipes without using the welding process. This approach is commonly used for pipe grooving and threadless fittings in applications such as refineries, locomotive/seismic, offshore, wind turbines, steel/power plants, etc…All these are industries that require the highest accuracy and safety.
Next, what are the advantages of weldless piping technology over welded fittings? Non-welded fittings will eliminate all the drawbacks of welded fittings that we mentioned earlier. Also, weldless fittings will help to create leak-free designs by eliminating the risk of residues and acid cleaning. Other benefits include ease of installation, high safety, improved flow characteristics, cost-saving, etc…
What are the different non-welded piping technologies? Flare flange fittings, retain ring flange connections, and radially crimped connections are mostly used types of weldless connections.
Non-weld flare flange connections are available at 35 degrees and 90 degrees depending on the manufacturer and system requirements. Systems with flare flange connections will flare the pipe ends to 37° (35-degree flare flange) and 90°(90-degree flare flange) by utilizing two internal cones and flanges. The easy-to-fabricate flare flange connections are ideal for thin-walled pipes in hydraulic applications.
Next is the retain ring flange connection, which is ideal for large bore high-pressure pipes. The design contains a butt end face, containing an annular groove on the outside diameter. The leak-free connection is created by slipping the flange onto the pipe and the retain ring is sprung over the pipe’s outside diameter., which is ideal for large bore high-pressure pipes. The design contains a butt end face, containing an annular groove on the outside diameter. The leak-free connection is created by slipping the flange onto the pipe and the retain ring is sprung over the pipe’s outside diameter.
The 360° radially crimped connection is another non-weld fitting approach, which is ideal for both high-pressure and low-pressure applications. These connections will increase the installation speed, reduce downtime, improve safety standards, etc…