Generally speaking, pipes with a diameter of less than DN100 use a threaded connection, and fire pipes with a diameter of ≥100 use a clamp type connector interface.
Fire hose pipe with a diameter ≥ DN100 used screw connection in the past, which was very difficult to construct. This is due to the large diameter, shallow thread at the pipe interface, weak connection, easy to leak, and deep thread, the thread at the interface The wall of the tube is too thin to withstand the working pressure of the system and it is easy to break. Now, the specifications have been revised. As for economic analysis, the threaded interface is cheaper than the clamp connector interface. The clamp interface is the best method at present.
