Issues with the oil transfer line supports in the heating furnace

The following are the regulations set by a well-known domestic design institute regarding the design and stress analysis of the atmospheric and vacuum transfer lines in atmospheric and vacuum distillation units (hope this will be helpful). 2.1.1 The atmospheric and vacuum transfer lines in atmospheric and vacuum distillation units (hereinafter referred to as transfer lines) are important process pipelines in piping design, and close coordination and cooperation among all relevant disciplines should be emphasized throughout the design process. 2.1.2 The oil transfer line consists of a high-speed section and a low-speed section. When designing the oil transfer line, it is advisable to adopt new technologies that utilize furnace tubes to absorb as much of the thermal expansion of the line as possible, in order to reduce the pressure drop across it. 2.1.3 The layout of the pipes and the installation of supports should take fully into account the operational characteristics of the oil transfer line as a two-phase flow pipeline. 2.1.4 The route of the oil transfer line should be given careful consideration during the layout of the equipment. To control the temperature drop and pressure drop along the oil transfer line, its low-speed section should not be too long, but it must still meet the minimum length requirements specified in the process design for such lines. 2.1.5 The oil transfer line being a pressure pipeline, necessary strength calculations shall be carried out for its wall thickness, reinforcement rings, opening reinforcements, and supports in accordance with the various requirements and calculation methods specified in GB 150. 2.1.6 To prevent the liquid medium from accumulating in the low-speed section, this section should ensure a slope of 0.2% to 0.3% even after the hot tower interface rises. 2.1.7 When the diameter of the pipeline in the low-speed section is 800 mm or larger, a DN500 standard manhole shall be installed; its pressure resistance rating must be at least 2.5 MPa. The manhole should be located away from the tower end, and ladders and operation platforms shall be provided as necessary. 2.1.8 To reduce the horizontal thrust exerted by the oil transfer line on the equipment interfaces and supports, the supports for pipelines in the low-speed section should employ rolling friction or oil-free lubrication to minimize the friction resulting from relative movement. 2.1.9 If the low-speed section of the pipeline is too long, resulting in excessive thrust on the equipment interface, cold straining can be applied to this section. 2.1.10 When the pipeline in the low-speed section is too high (with a clearance of not less than 10 m), it is possible to consult with the civil engineering team to consider designing the supports as flexible structures. 2.1.11 Safety measures to prevent the pipeline from sliding laterally off its supports should be considered for pipelines in the low-speed section. 2.1.12 Pipelines in the high-speed section should be arranged symmetrically to reduce coking and vibration caused by uneven flow and deviation of the medium. 2.1.13 The connection between the high-speed section and the low-speed section should employ a special-shaped tee to reduce the flow resistance of the medium. 2.1.14 The special-shaped tee is a key component of the entire low-speed oil transfer line; it has high technical requirements and should be designed and manufactured as a special type of fitting. 2.1.15 To reduce the flow resistance of the pipeline medium in the high-speed section and the problem of stress exceeding limits caused by excessive stress concentration at elbows, elbow bends with a curvature radius R of 4DN to 6DN are recommended for use in such sections. 2.1.16 When the pipeline experiences significant vertical displacement, spring supports and hangers can be used. Suspension brackets should not be used in high-speed sections; the main supports in low-speed sections should be designed in the form of spring boxes. However, the entire oil transfer line should not be equipped entirely with spring-type supports. 2.1.18 The structural loads on the support and hanger systems of the oil transfer lines shall take into account the loads resulting from water filling and emergency situations (such as tower flooding), and protective measures shall be taken for the springs. 2.1.19 Lightweight insulation materials should be used for the insulation of the oil transfer line. 2.2 Stress analysis of the oil transfer line 2.2.1 Accurately calculate the displacements of the pipeline at each end in all directions under normal operating conditions. 2.2.2 When considering the use of displacement of the heating furnace tubes to absorb part of the thermal expansion of the oil transfer line, the stress analysis may include some of these tubes; the displacement and stresses experienced by the heating furnace tubes shall be provided by the piping team to the furnace team for verification. 2.2.3 The force exerted by the oil transfer line on the tower shall be submitted to the equipment specialty for confirmation. 2.2.4 The springs selected for spring supports and hangers should minimize the variation in load between the installed condition and the cold condition. 2.2.5 When the diameter of the low-speed section of the oil transfer pipeline is not less than 1 m and its height is not less than 10 m, wind loads shall be considered in the stress analysis, and the allowable stress value shall be selected in accordance with SH 3059. When it is not possible to calculate the wind load, the static calculation should take into account a margin of not less than 20% of the allowable stress. 2.2.6 When the oil transfer line is made of stainless steel composite plate (with DN not less than 500), its allowable stress shall be determined according to the calculation method in Chapter 3 of GB 150-1998.

The suggestions on the 2nd floor are quite detailed; one can follow them. However, stress calculations must be carried out for the design of this pipeline, and the type of supports can be determined through consultation with the person in charge of the stress calculations.

The second floor provided quite detailed information; to determine what kind of support structure should be designed, it is first necessary to have an understanding of the characteristics of the project

The explanation on the second floor was really detailed. Before, I only knew that this area was important, but this time I truly learned something about it