The difference between the rigid clamp and the flexible clamp is that the flexible clamp will compensate for the thermal expansion and contraction of the flexible clamp in the pipeline.  

The clamps and rigid (flexible) joints in the groove connection are almost the same in appearance, but the uses are different. The flexible joint allows the pipeline to have some axial displacement and corners, so that the pipeline is flexible, while the rigid one cannot.      

The piping system using rigid clamp joints is in a rigid state, that is to say, the pipe cannot produce axial and radial displacement, and the system is not flexible. After the pipe clamp is clamped, it can form a rigid whole with the steel pipe. When the span of the spreader is large, it can ensure that the pipe is connected by its own rigid support. This kind of pipe fitting is mostly used for the connection between the riser and the general pipeline system.   

Let's look at the flexible clamp again. After its joint is connected to the pipe, it allows the pipe to have some axial displacement and rotation angle. The use of this pipe fitting can make the system in a flexible state. Gap, leaving room for expansion and contraction of the pipeline. The pipe card should maintain normal working pressure under the condition that it is allowed to stop and dislocate.