The machining of valve flanges is a very critical link in the valve manufacturing process, involving the connection of valves to pipelines or other equipment. Flanges are annular components used to connect valves to pipelines, usually with several holes for bolt connection. The machining quality of flanges directly affects the sealing, strength and durability of valves, so the precision and machining process requirements are very high.
The material of the flange is usually the same as that of the valve. Common materials include carbon steel, stainless steel, cast steel, alloy steel, etc. Different materials require different machining methods and tools. Common shapes of valve flanges are flat flanges, butt welding flanges and blind flanges. Flange machining has multiple steps. The outer circle of the flange needs to be flat and meet the design dimensions, which is often completed by lathe or CNC lathe. The size and finish of the inner hole are required to be high, and it is necessary to ensure good fit with the pipeline and valve body. It is usually processed by lathe or milling machine. The number, diameter and hole spacing of the bolt holes on the flange are very important. Generally, the diameter accuracy of the holes is required to be high and the hole spacing is uniform. It is usually processed by CNC milling machine or drilling machine. The hole processing process includes drilling, reaming, tapping and other processes to ensure the accuracy and position of the hole.
The flange surface is mainly used for sealing contact with other equipment or pipeline flanges, so it must have good flatness and roughness. Common flange surface types include flat flanges, concave and convex flanges and grooved flanges. The processing of the flange surface usually uses CNC milling machines or CNC lathes to ensure that the flatness and surface roughness of the flange surface meet the requirements. After the flange is processed, it needs to be chamfered, especially the orifice part, to avoid sharp edges. Use a grinder or chamfering machine for chamfering, and then remove the burrs generated during the cutting process to avoid burrs affecting the sealing.
The machining of valve flanges requires a high degree of precision control to ensure that the size, shape and surface quality of the flange meet the requirements. Commonly used equipment for processing includes lathes, milling machines, drilling machines, and CNC machine tools. Factors such as the flange's connection hole, sealing surface and flatness are crucial to the sealing performance and durability of the valve, so they need to be processed and inspected in strict accordance with relevant standards.