Pipe fittings are connecting tools between pipes, serving as detachable connection points between components and pipes. They play an indispensable role in pipe fittings and are one of the two main components of hydraulic pipelines. Pipe fittings are used for straight connections in instruments, etc., with connection methods including socket welding or threaded connections. They are mainly used in small-diameter, low-pressure pipelines, in areas requiring frequent assembly and disassembly, or for final adjustments in pipelines using threaded fittings. The preferred structural form is a metal-to-metal contact sealing structure; gasket sealing structures are typically used in pipelines transporting water, oil, air, etc., and are made of malleable cast iron. In addition, usage requirements and price are also factors to consider when selecting fittings.
There are many types of pipe fittings, commonly divided into rigid pipe fittings and flexible hose fittings. Based on the connection method between the fitting and the pipe, rigid pipe fittings include flared, compression, and welded types, while flexible hose fittings are mainly crimped hose fittings.
The connection methods between pipes and pipe fittings in hydraulic systems also differ; the screw-in end of the pipe uses a connecting thread. Tapered threads, tightening with their cone-shaped structure and sealing with materials like PTFE, are primarily used in low- to medium-pressure hydraulic systems. Fine threads offer excellent sealing and are frequently used in high-pressure systems, but require the use of combination washers or O-rings for end-face sealing; sometimes copper washers are also used. They are more suitable for connecting pipes with thicker walls. Their main components include a fitting body, a connecting pipe, and a nut. In use, the fitting body is inserted into the target, and the aforementioned washers are used to seal the end face. A rubber seal is used between the fitting body and the connecting pipe; sometimes a spherical seal is also used.
Because pipe fittings are detachable connection elements, in addition to meeting requirements such as stable connection, strong sealing, reasonable size, low pressure loss, and good processability, they must also be easy to assemble and disassemble. Therefore, don't underestimate these small pipe fittings, as they are essential to the entire hydraulic system.
