What is the working principle of the expander

Expander taper. A, expanding bead taper, flap expanding bead taper shell open three expanding bead holes, in order to make the expanding bead through the bead holes and tube wall contact, bead hole centerline and shell bus into one. Intersection angle, so as to ensure that the center line of the expansion bead and the center line of the expansion rod into the intersection angle of the mouth ' angle called the propulsion angle of three holes to. Distributed flap expansion bead propulsion angle can take the value of zero reasonable expansion process is, first of all, the use of fixed expansion expansion device expansion, so that the tube and the tube hole to eliminate the gap between the question, to achieve the bamboo and the initial fixed seal of the tube hole wall, and so on all the tubes and the coupling box tube plate are fixed expansion, the second step is to use the flap expansion of the bamboo device to unify the flap expansion. Flap expansion is a key link in the expansion process, through the flap expansion, so that the tube and the coupling box, pipe plate connection up to the expansion rate specified in the procedure to ensure that the tube and pipe plate expansion at the seal expansion rate is expressed after the expansion of the plastic deformation of the tube and pipe plate elastic deformation of the degree of the technical indicators of the seven plate mountain in the elastic deformation produced by the center of the radial compressive stress pointing to the tube holes. The elastic deformation of the seven plates in the elastic deformation of the radial compressive stress pointing to the center of the tube hole, then tightly hooped by the outer wall of the tube has been expanded, so that the tube and the hole wall of the formation of a tight and strong connection, and thus achieve the purpose of sealing and resistance to pull off. If the elastic deformation of the pipe hole wall is too small, then the work of the pipe will be hard enough to have the possibility of leakage, at this time, according to the regulations can be carried out once or twice to make up for the expansion. If the pipe hole wall is subjected to excessive radial force and produce a large range of plastic deformation, then its elastic recovery instead of poor, thus weakening the fastening force between the two, the expansion of the sealing performance of the joints instead of decreasing, that is, the so-called "over-expansion". Expansion of the mouth in the hydraulic test will appear seepage, water leakage and many other problems in this case can not be used to continue to make up the expansion to eliminate leakage, otherwise it will only lead to a more serious "over-inflated" Therefore, flanging the service bamboo when the control of the rate of expansion is very important to grasp the rate of expansion of the measures is to control the flanging expansion of axial advancement of the expansion rod. In the medium and low pressure set strike assembly in general through the unified control of the flange expander out of the pipe hole wall a distance, that is, "device distance" to ensure. When the flanging expander fully advanced to the tube, to achieve relative to the center line of the tube flanging into, expanding the rod to the tube also pushed a greater than the distance of the axial amount of wire due to expanding the rod is a cone, expanding the rod's axial advancement, providing a certain amount of radial displacement of the expansion bead, by expanding the bead on the needle wall rolling, to achieve the tube and the hole wall of the strong strong coupling in order to ensure good quality flanging, the tube end should be carried out ℃ . ℃ annealing treatment of dark red, annealing length is generally, after removal and inserted into the dry sand slowly cooled control device distance value approximates the expansion rate in the nominal pressure of the corpse, the assembly of high-pressure equipment, the rate of expansion must be mastered by the axial feed of the expansion rod to accurately control the amount of control by the technical specifications of the group. Transportation