Material requirements of axial external compression type bellows compensator

Material requirements of axial external compression type bellows compensator
In the pure axial external compression type bellows compensator, under the action of the external force distance M, the outer arm wall of the neutral layer of the material is subjected to tensile stress &1 decreases and the compressive stress in the arm decreases. The material thickens and N1 and N2 change the tube cross section. Therefore, the main reason for the decrease in quality of axial external compression bellows compensator is RX and SX. For this reason, GBJ235-82 clearly specifies the RX and outer thinning of different pressure levels to control the RX and SX values, so as to ensure quality.
Material when the material is pulled on the outside, the position of the neutral axis of the inner pressure is different from the axial external pressure type bellows compensator way, when the top bending work, the neutral axis is about 1/3 from the outer wall, when the spin bending (back bending) work, the neutral axis is about 2/3 from the outer wall. thus, favoring the material thin-walled pipe.
In the field construction, the operator also understand the processed pipe material, processing properties and surface corrosion. Immediately provide R. Axial external pressure type bellows compensator radius / pipe outer diameter relationship graph for the user to choose the relationship between pipe diameter and wall thickness for reference. This chart mainly discusses the influence of relative material radius and relative thickness on the quality of axial external compression type bellows compensator.
According to the pipeline processing acceptance specification, axial external compression type bellows compensator for medium and low pressure 4D, high pressure 5D. axial external compression type bellows compensator for R = 4D (special case is determined separately), so the axial external compression type bellows compensator, the main choice of relative wall thickness SX, the upper part of the chart is the mandrel-free area, the middle of the chart is the mandrel-free area, the lower