Clampers are mainly used to tighten the pipe ends during the construction of Krauss pipes, so that the hot melt net on the inner wall of the spigot joint is tightly connected, thus achieving sufficient contact for hot melt welding. With the Krauss pipe welding machine, the clamper locks tightly, the pipe ends fit well, the sealing effect is good, the construction is simple, fast and convenient, and even new workers can quickly master the use skills.