Acid cleaning of oil pipelines
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The new oil pipes in my workshop need to be pickled. Generally speaking, why is it necessary to pickle oil pipes? I only know that it’s done to prevent corrosion, but lubricants shouldn’t be very corrosive, right?； I would also like to ask the fellow sailors: how is pickling carried out?
Maybe pickling first and then applying anti-corrosion treatment
Professional companies handle acid cleaning; a pump is used for system circulation, and temporary pipes need to be installed
The purpose of pickling is to remove impurities such as oxides from inside the pipes, revealing the true color of the pipe wall.
I agree with the person above; pickling is the process of removing oxides and mechanical impurities from pipes.
The lubricating oil pipelines require a high level of cleanliness; they are generally made of stainless steel, and it is necessary to carry out acid washing and passivation in order to prevent impurities introduced by the lubricating oil from affecting the sealing of the equipment. Pickling is carried out using strong acids (*ao acid, aqua regia, etc.) to achieve passivation (through internal circulation or immersion in a pickling tank), thereby forming a passivation layer on the inner surface of the stainless steel pipeline. Internal impurities are washed away from the pipe due to the action of the acid, resulting in internal cleanliness.
Generally, the oil pipes in compression units are made of stainless steel. I only know that oil flushing is required (connecting the pipeline to the unit, installing a filter on the return oil line; after flushing is successful, cleaning the oil tank and replacing it with new oil). I’ve never seen acid washing being used, though
It is washed with a chemical cleaner, in order to remove oil and rust and ensure that the process fluid remains unpolluted
If circulating water is used, cleaning is also necessary; otherwise, pre-coating cannot be completed.
I came here to learn*; I’ve never seen the pickling process before. I think it should start with alkaline cleaning to remove oil and grease, followed by pickling to remove rust, then washing, steam drying, and replacement with an inert medium
For pickling, refer to the national standards and petrochemical industry standards for mechanical equipment installation specifications. Primarily, during the procurement, transportation, or installation of pipes, pipe fittings, and valves, grease, dirt, and debris (such as soil particles and welding slag) as well as other substances that are harmful to lubricants can be generated. These substances can cause damage to the equipment while it is in operation.