The LNG unloading arm is an important channel connecting the carrier and the LNG receiving station pipeline to transport liquefied natural gas, which is called the "throat" of the receiving station. In this paper, The finite element structure of the unloading arm is calculated and analyzed for the first time, and some design optimization suggestion is given. There is a large stress concentration at the joint of the three-dimensional joint and the pipe of the outer arm, the structural design process should be paid attention to. The structural strength of the lengthening position of the support box is weak, a pipe with thicker wall should be used. Aiming at the emergency release system of the key core components of the unloading arm, an innovative hoop locking mechanism is designed based on the principle of mechanical dead point, and finite element calculation and performance test results show that the stress and deformation of the hoop locking device meet the design requirements, and that its stability and reliability also meet the needs of the unloading arm operation, thus providing a reference for safe and reliable operation of large LNG unloading arm.

liquefied natural gas  /  unloading arm  /  emergency release system  /  hoop locking device  /  reliability