1. Factors Affecting Installation Quality
(1) The vacuum clamp shall not have defects such as pores, sand holes, shrinkage cracks, etc.
(2) The material and performance of the centering ring must meet the requirements. There should be no air bubbles, impurities, cracks, or uneven defects on the sealing surface, and aging rubber rings should not be used.
(3) The moving distance of the snap ring in the vacuum clamp is theoretically half of the expansion and contraction of the joint. The actual amount should be measured. If it cannot be reached, it cannot meet the expansion and contraction requirements of the pipeline. In order to promote the sealing effect, the left and right end pipes are matched with the vacuum clamps before leaving the factory. In actual engineering, it is not suitable to use ordinary pipes to directly replace the end pipes, and the verticality of the end face of the end pipe and the axis and the flatness of the end face itself has certain requirements. The standard greatly reduces the expansion and contraction of the joint, which cannot meet the requirements of use.
(4) Positive deviation should be selected for the diameter of the end pipe, otherwise, the pressing force of the vacuum clamp on the sealing ring is not enough, which will affect the sealing effect of the fittings.
2. Precautions when installing the vacuum clamp
(1) To control the distance L between the snap ring and the end pipe. The control of L should be combined with the manual. When the gap between the two pipe ends is the smallest, it is necessary to ensure that the snap ring just sticks to the inclined surface.
(2) When the position of the snap ring is determined, the size of the gap between the two pipe ends shall be determined by calculation according to the elongation rate of the pipe and the ambient temperature during construction. Dimensional deviation should be guaranteed during construction.
(3) Under the premise of a certain moving distance, the greater the error in the height and width of the weld seam welded between the snap ring and the end pipe, and the perpendicularity between the plane of the snap ring and the axis of the end pipe, the smaller the expansion and contraction of the joint, and the worse the use effect.
(4) The splash impurities during the welding of the end pipe and the snap ring will affect the sealing of the end pipe. Before installation, the welding slag on the sealing surface should be cleaned to ensure the sealing effect.