The application of slant bed CNC lathe in the field of flange processing

Recently, our company received an inquiry, there is a flange manufacturer customers to find us, his customers need to process the flange, we are required to provide the ability to process the diameter of 40cm flange with holes in the machine, after our engineers to communicate and understand, matched with a suitable slant-bed CNC lathe, able to meet his processing needs.

What is Flange?

Flange is a disk-shaped part, which is usually installed at the end of pipelines, valves, pumps, pressure vessels and other equipment, used to connect two parts, so that they can be tightly connected together, and can be easily disassembled and maintained. Its shape is usually round, there are also square or rectangular flanges, but relatively few. The flanges usually have holes around the periphery for mounting bolts, and the two flanges are tightly connected together by bolts, nuts and gaskets.

Structure of flange

Flange Body: This is the main part of the flange, and its thickness varies according to factors such as usage scenarios and pressure levels. For example, in low-pressure piping systems, the flange body may be relatively thin; while in high-pressure piping systems, such as high-pressure transmission pipelines for petrochemical industry, the flange body needs to be thicker to withstand great pressure.

Bolt holes: distributed around the outer circumference of the flange body, their number, size and distribution also depend on the standard of the flange and the application scenario. Generally speaking, the higher the pressure and the larger the diameter of the flange, the greater the number of bolt holes may be. These bolt holes are used for mounting bolts so that the flanges can be tightly connected.

Advantages of CNC turning for flange machining on slant beds

Advantages of high precision machining

High dimensional accuracy: When machining flanges on slant-bed CNC lathes, due to its bed structure and high-precision CNC system, it can accurately control the movement trajectory of the tool to ensure the dimensional accuracy of the flanges. For example, for key dimensions such as the outer diameter, inner diameter and thickness of the flange, the error can be controlled within a very small range, and the tolerance can usually reach ±0.02mm or even higher precision. This is essential for the tight connection and sealing performance of flanges in, for example, piping systems.

Good shape accuracy: When machining some special shape flanges, such as flanges with flange, groove or asymmetric structure, the slant-bed CNC lathe can ensure the shape accuracy very well. Through precise programming and advanced servo drive system, the tool cuts accurately along the designed path to ensure the flange’s flatness, cylindricity and other shape accuracy indexes. For example, the flange flatness error can be controlled within 0.01mm, and the cylindricity error can reach a similar high precision level. Such high precision shapes help the flange’s stability and sealing during installation and use.

Good rigidity and stability

Advantage of bed structure: The bed structure of slant-bed CNC lathe has better rigidity than the traditional flat-bed lathe. The slanting bed design makes the lathe better able to withstand the cutting force during the machining process. In the processing of flanges, especially large-size, thick-walled flanges, the cutting force is larger, the slanting bed structure can effectively reduce the deformation of the bed. For example, in the rough machining of carbon steel flanges with larger diameter (such as more than 400mm) and thicker thickness (such as more than 50mm), the slanting bed CNC lathe can maintain a stable cutting state and avoid machining errors caused by bed deformation.

Strong vibration suppression ability: due to the slant bed structure and reasonable machine layout, this kind of lathe has a better vibration suppression effect. In flange machining, vibration may lead to deterioration of surface roughness and decrease of dimensional accuracy. Slant-bed CNC lathe can effectively reduce the vibration between tool and workpiece through its own rigid structure and some auxiliary vibration damping measures (such as adopting high-precision ball screws and linear guideways with vibration damping devices). For example, when turning flanges at high speed, its machining surface roughness Ra value can reach below 1.6μm, which ensures the surface finish of flanges.

Efficient machining performance

High-speed cutting ability: slant-bed CNC lathes usually have high spindle speeds and fast feed speeds, which make it capable of high-speed cutting in flange machining. For some flange materials with softer materials (such as aluminum alloy flange), high-speed cutting can be utilized to improve machining efficiency. For example, the spindle speed can reach several thousand revolutions per minute or even higher, which, together with the appropriate tooling, enables rapid material removal and shortens machining time.

Multi-process integrated machining: This type of lathe is able to complete multiple processes of flange machining in one clamping. For example, for a flange with multiple features such as internal and external rounds, flat surfaces, and sealing grooves, it is possible to start with external turning, followed by internal round machining, and then sealing grooves and flat surfaces, without the need for multiple re-clamping. This not only improves the machining efficiency, but also reduces the positioning errors caused by multiple clamping and ensures the relative positional accuracy between the various parts of the flange.

Convenient programming and operation

High programming flexibility: slant-bed CNC lathe is programmed with CNC system, for the different shapes and sizes of flanges required, the programmer can flexibly write the machining program according to the design drawings. Whether it is a simple round flange or a complex shaped flange, it can be accurately machined by suitable programming instructions. For example, for a flange with special curve contour, the programmer can easily realize the machining of complex contour by using the macro program function in the CNC system or the program code generated by CAD/CAM software.

Friendly operation interface: the operation interface is generally designed to be more intuitive, and the operator can operate it skillfully after certain training. During the flange machining process, the operator can easily adjust the machining parameters, such as cutting speed, feed and depth of cut. At the same time, the CNC system can also display the processing status in real time, including tool position, remaining processing volume and other information, which is convenient for the operator to find out the problems and deal with them in time.

 According to the customer’s needs, we finally matched TCK50A/500, which is a mature product mainly exported by our company, with compact structure, beautiful and pleasant appearance, high torque spindle, high rigidity, stable and reliable performance, and excellent accuracy retention. Adopting 30° whole inclined bed structure, equipped with high-precision pre-loaded Taiwan linear roller guideway, the machine is characterized by high positional accuracy and smooth chip removal suitable for high-speed and high precision machining.

Keywords: CNC lathe, Slant bed CNC lathe, CNC lathe for flange machining