According to different connection method, metal hose can be divided into: flange type, thread type, quick coupling type and welding type.

1. Flange type: for metal hose whose diameter is above 25mm, in condition of bearing general working pressure, flange type is the main type. Its sealing model is matching with mortise. It has good sealing performance, but high processing difficulty, sealing face is easy to injured.

2. Thread type: for metal hose whose diameter is below 50mm, in condition of bearing higher working pressure, thread is the best choice. When screw down the thread, the inner and outer taper face fit closely, in this way to achieve sealing. Generally taper angle is 60 degree, also has 74 degree. Although thread type has better sealing property, when installation, it must maintain the concentricity of butt joints.

3. Quick type: for metal hose whose diameter is below 100mm, suitable for place where need quick dispatch. It use O sealing ring to seal which is made by fluoroplastic or special rubber. It is especially suitable for environment such as fire ground and battlefield. You only need several seconds to separate or butt joint a set of joints.