The formula involved in the selection of bellows expansion joint
(1) thermal displacement at the interface of the equipment. The pipe and equipment are located in a three-dimensional installation space of x, Y and z, so there are three thermal expansion displacements at the interface points:
Where, D -- is the distance from the fixed point of the device to the interface point; Ding refers to the coefficient of thermal expansion; A is the temperature difference between the device temperature and room temperature.
(2) thermal expansion of pipelines. Pipe will expand when heated and its expansion formula is: delta T = 0 [T delta TL, delta T, the expansion of the pipe when temperature T, m m; only - pipe materials in the linear expansion coefficient, when temperature T m m/m m. ℃. Often think of 20 ~ C in engineering at zero relative thermal expansion coefficient, and the temperature changes of thermal expansion coefficient is relative to the 20% of the thermal expansion coefficient, linear expansion coefficient of linear expansion can be reference table. The length of the pipe, I m m. It should be a pipe in the space in a coordinate direction projection length.
(3) displacement of expansion joint. N1. Single hinged expansion joint. The calculation formula is as follows:
Note: ASME standard is used for civil pipelines, and CAESAR II is used for mechanical calculation software; Nuclear power pipeline USES RCCM standard and mechanical calculation software SY SPIP234D.