Analysis of Expansion Joints Movement Test in FCC Unit

Abstract

The turboexpander is an equipment that works under very critical conditions requiring very low allowable nozzle forces and moments. A solution to minimize the piping loads transmitted to the equipment is the use of expansion joints (EJ). A usual piping stress analysis normally is not enough to guarantee the turboexpander reliability. This paper shows the results obtained in a movement test realized on metallic bellows EJ used in a turboexpander piping system. The EJ were designed according to the expansion joints manufacturer association code (EJMA), the diameters range from 0.457 to 2,898 m, the material of the bellows is Inconel 625 LCF and the shell materials are “killed” carbon steel, for refractory lined EJ or stainless steel 304H. A special test device was developed to apply the design movements on the EJ at the factory. A digital dynamometer was used for data acquisition and the tests were performed on 16 EJ of two distinct types: hinged and gimbal. The EJ were pressurized with water during the test. The reactions and corresponding displacements for each step of the test were recorded during loading and unloading.

A combined numerical and experimental study on metal expansion bellows for STHE

“…Igi [5] proposed a double convolution bellows to reduce excessive deformations due to heat expansion, vibration, nonuniform subsidence of ground, etc., whereas Newland [6] studied buckling analysis of corrugated bellows expansion joints subjected to internal pressure. A distinct test device was industrialized in [7] to smear the design movements in a turbo expander piping system in which the reactions and corresponding displacements test were recorded during loading and unloading, whereas the effect of the elliptic degree of Xshaped bellows toroid on stresses has been probed in [8]. Faraji et al [9] proposed a novel method of bellows manufacturing with investigation of various materials by finite element analysis (LS-Dyna) and trials, whereas a single-step hydro-forming process is proposed in [10] for various shapes of tube-shaped bellows.…”