There are many types of pipe fittings, which are classified according to use, connection, material, and processing methods.
By purpose
　　1. The pipe fittings used to connect the pipes are: flanges, unions, pipe clamps, ferrules, hose clamps, etc.
　　2, pipe fittings that change the direction of the pipe: elbow, elbow
　　3. Fittings that change the pipe diameter: reducing diameter (reducing pipe), reducing elbow, branch pipe stand, reinforcing pipe
　　4. Increase the pipe fittings of the pipeline branch: three-way, four-way
　　5. Fittings used for pipeline sealing: gaskets, raw material tape, wire hemp, flange blind plates, pipe plugs, blind plates, heads, welding plugs
　　6. ​​Pipe fittings used for pipe fixing: snap ring, towing hook, lifting ring, bracket, bracket, pipe clamp, etc.
　　 divide by connection
　　1, welded pipe fittings
　　2, threaded pipe fittings
　　3, tube fittings
　　4, clamp pipe fittings
　　5, socket pipe fittings
　　6, bonding pipe fittings
　　7, hot melt pipe fittings
　　 8. Rubber ring connection type pipe fittings
　　 divided by material
　　1, cast steel pipe fittings
　　2, cast iron pipe fittings
　　3, stainless steel pipe fittings
　　4, plastic pipe fittings
　　5, pvc pipe fittings
　　6 Rubber pipe fittings
　　7, graphite pipe fittings
　　 8. Forged steel pipe fittings
　　9, PPR pipe fittings,
　　10 alloy pipe fittings
　　11, pe pipe fittings
　　12, ABS pipe fittings