【Common Issues in Haichuan Pipeline Design】--Fire protection pipelines fixed to storage tanks lack support, causing sagging and severe deformation of the flexible connections

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During the design, installation, and inspection of pipelines, various minor issues that have been overlooked or not taken into consideration are often identified. These issues are compiled into a series, which is being continuously updated. Everyone is welcome to actively participate in discussions. This is a compilation post on common problems in Haichuan pipeline design; it’s still being updated, and discussions are welcome: https://bbs.hcbbs.com/thread-5705828-1-1.html ------------------------------------------------------------------Basis for determination: \"Guidelines for Selecting Pipe Diameters in Petrochemical Process Units\", SH/T 3035-2018, Section 6.4 – Flexible joints must be free from twisting, excessive stretching, cracks, and dead bends. Code for Acceptance of Construction Quality of Building Water Supply, Drainage and Heating Engineering GB 50242-2002 11.2.10 Flexible connectors shall be installed firmly, without any signs of forced twisting, bulging, or distortion. SH/T 3007-2014 \"Code for Design of Tank Areas in Petrochemical Storage and Transportation Systems\" 5.3.10 Flexible connections shall be installed naturally; they must not be forced to stretch or compress, and a margin for expansion and contraction should be provided. Code for Design of Industrial Metal Piping GB50316-2000 (2008 edition) 6.1.1 Piping shall be provided with necessary supports and hangers to bear loads such as the weight of the piping itself and the weight of the medium, thereby preventing excessive deflection, sagging, and abnormal deformation of the piping. According to GB 50235-2010, Code for Construction of Industrial Metal Piping Projects, 8.0.1: Support and hangers shall be installed for piping in accordance with the design specifications; the piping must not be laid without any support, and it is strictly prohibited for the piping to hang freely or exhibit excessive bending. \"Code for Design of Supports and Hangers for Petrochemical Piping\", SH/T 3041-2016, 3.1 The piping system shall possess sufficient flexibility under various operating conditions; it must not suffer from the following problems due to thermal expansion and contraction, additional displacements at the ends, or improper installation of piping supports: a) Excessive pipe stress or pipe failure caused by metal fatigue ； b) Leaks at pipe connections ； c) Excessive pipe thrust and/or torque cause excessive stress or deformation in the equipment connected to it, affecting the normal operation of that equipment ； d) Excessive pipe thrust and/or torque cause damage to the pipe supports and hangers. Improvement suggestion: Install support points in front of the flange of the inlet pipe that is flexibly connected to the storage tank, to prevent the flexible connection pipe from sagging and deforming due to the lack of support on the inlet pipe.