Discussion on pipeline pickling and passivation methods
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Regarding the acid cleaning and passivation of pipes, there are currently two main methods: 1. The pipe is inserted into the acid cleaning tank; generally, the pipes are connected using flanges, and after the flanges are welded to the pipes, they are then inserted into the acid cleaning tank； 2. Circulating acid cleaning and passivation of the pipeline system: After all the pipes have been welded together, a certain proportion of chemical agents is added to the pipes and a circulating treatment is carried out. 1. Are there any other acid cleaning and passivation methods besides those mentioned above? 2. What are the advantages of each? 3. If pipeline circulation acid cleaning and passivation is used, are the valves and other valve components in the pipelines removed before the acid cleaning and passivation? 4. For pipes with cleanliness requirements, such as clean steam or clean oil-free air compressors, are there any other special requirements?
Immersion is not penetration; it is generally used for acid cleaning of randomly laid pipes in equipment, or for the sections of a system that need to be taken apart during acid cleaning. In industry, system circulation acid cleaning is commonly employed for pipeline systems. One advantage of this method is that the entire system can be treated without having to remove the valves; however, control valves and other instrumentation do need to be removed. After acid cleaning, steps such as passivation follow, followed by cleaning, drying, and nitrogen protection
I would like to ask how to check the quality of acid washing and passivation?
Could you please provide details on the detailed process for pipeline pickling and passivation? Also, which pipelines need to undergo pickling and passivation (based on design requirements or as required by standards)? Thank you!
De-fat and degrease, then pickling, then washing, then passivation, then washing again, and finally drying with oil-free compressed air
I also want to know what standards specify which pipes need to be pickled