【Weekly Topic】【Static Equipment Discussion Forum...Question 3】 December 24-31, 2018...Secondary processing issues – Sea Coin rewards
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bg13.jpg【Weekly Topic】【Static Equipment Discussion Forum...Question 3】 December 24-31, 2018...Issues related to secondary processing – Do not repeat others’ posts; do not post content unrelated to the topic; do not reply with meaningless messages. Reward rules: HAICHUAN coins are awarded based on quality, ranging from 1 to 30 points. Please participate actively – don’t hold back! Multiple people can score (based on wealth, charm, and HaiChuan coins). During the design process, it is inevitable to discuss the issues related to the secondary processing of flanges, fins, and other components. Different people have different views; what matters is participation. Response format: 1. Which equipment structures and parts require secondary processing?--------------------------------- 2. What are the factors that lead to the need for secondary processing?----------------------------------------------- 3. Can other measures be taken to replace secondary processing, and if so, how?---------------------------------- 4. Can examples, both in text and images, be used to illustrate the above issues?------------------------------------------------ Try to keep the response neat and easy to read.
Isn’t it a bit like this: Specialization leads to mastery, while brief writings give rise to shifting thoughts. ;P
1. The mounting of the ear mounts does not match the on-site location, requiring the ear mount pads and even the ear mounts to be remade. 2. The location and orientation of the drilled connection pipe are inappropriate, requiring re-drilling. 3. Some flanges are damaged during transportation and lifting, and need to be remanufactured and replaced. 4. Sometimes, during the installation of connectors, the interfaces are modified within the limits permitted by the process requirements, in order to avoid conflicts in the pipeline layout.
Focus on manufacturing quality, with an emphasis on improved processing. For example, leaving a machining allowance for the sealing surface on the flange, and then performing secondary machining of the sealing surface as a whole after the parts are assembled.
Let’s start with a few that are used in normal contact: 1. The sealing surface of the tube sheet flange with a partition. (Stainless steel is processed directly, while carbon steel undergoes secondary processing after heat treatment) ； 2. The sealing surface of the reactor frame flange. (If it is a dispersion tank or similar, several sealing surfaces and the head should be welded together first and then processed to ensure that the sealing surfaces of the reaction and dispersion units are in the same plane.) ； 3. Packed tower sections. (If conditions permit, such as regarding diameter or length, the flanges on both sections of the tower segment should be processed uniformly after welding to ensure the straightness of the segment.) ； 4. Sealing surface of the gasket flange ；
1. Non-mechanically formed parts such as sheet metal cylinders with high precision requirements； Such as the inner cylinder of the quench ring in the gasifier. 2. To avoid the effects of heat treatment and welding, secondary processing is carried out after the assembly and heat treatment of the components are completed. For sealing surfaces with high requirements such as flatness or roughness, the third step ensures the overall tolerance of the assembled parts, with further processing carried out after the components are assembled. After the heat exchanger is assembled, the pipe ends should be mechanically processed as a whole to ensure flatness. 4. To achieve certain special functions, secondary processing is carried out after completion. Such as surface strengthening, chromium carbide coatings on certain parts of impellers or turbine blades; coatings are added to surfaces with high erosion resistance requirements.
1. Large flanges or thin flanges of large diameter welded to thin-walled containers generally deform after welding, often requiring further processing； 2. The inner wall of the socketed small nozzles used on high-pressure vessels is thick, and quality issues tend to occur at the root portion; thus, secondary processing is often required, involving the removal of a portion of that area ；
For components that require surfacing, secondary machining is necessary after the surfacing process; for example, tube sheets may deform after surfacing, and secondary machining is required to ensure flatness as well as the perpendicularity of the tube sheet’s sealing surface to the axis； After surfacing of the equipment flange, machining of the sealing surface and stud holes