1. Clamping connection --------- It is divided into single clamping and double clamping. Double clamping is the most stable connection method. Use radial contraction force (hydraulic clamp) to clamp the pipe on the pipe, and pass the water stop of the O-ring to achieve the connection effect. Easy to operate, good sealing and non-removable.

2. Ring expansion type connection---------Use radial contraction external force (hydraulic pliers) to clamp the pipe fittings on the pipe, and pass the water stop of the wide band rubber sealing ring to achieve the connection effect, detachable, pipe The process of installing and increasing the rolling convex ring of the pipe end; the sealing performance is general, and the cost of casting pipe fittings is high.

3. Welded connection---------The hot-melt process is used to weld the two connecting parts to achieve the effect of connection. The connection strength is high, and the gas protection of the weld seam at the on-site welding port is difficult to meet the standard, which makes the weld seam easy to rust, which directly reduces the service life of the pipeline; the installation quality is highly dependent on the skills of the welding workers, and the quality is difficult to stabilize

4. Self-locking connection - firstly used for small-diameter plastic hose connection, quick installation without tools. The inside of the interface is easy to loosen and leak, and the sealing performance is poor.