Why some stainless steel pipes need degreasing

We all know that when stainless steel pipes are shipped from the factory, they need to be pickled and passivated. However, sometimes the user is asked to re-degreas the pipe? As far as the pipeline is concerned, a more reasonable degreasing should be done on site, that is, after the pipes are completely installed, degreasing is performed in the entire pipeline system. Generally do not let the manufacturer to carry out the degreasing treatment, then, ask the manufacturer to degrease the pipeline what is the matter?
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Degreasing stainless steel pipe
With the increasing level of industrialization in China, and the vigorous development of petrochemical, natural gas, medical equipment, instrumentation, aviation, aerospace and other industrial projects, the requirements for the stainless steel pipeline technology are also increasing. Such as the cleanliness of the pipeline, there are users can not have internal free rust, large particles of dust, welding slag, grease and other impurities.
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Use oxygen pipeline coal chemical industry
The oxygen pipeline cleanliness requirements are quite demanding. Oxygen pipelines mostly transport oxygen with a purity of more than 99.99%. The pressure is high and the flow rate is fast. If the interior of the pipeline cannot be cleaned, trace amounts of oil and metal ions in the pipeline may oxidize and collide with high-pressure pure oxygen and generate sparks. The unthinkable serious consequences even led to heavy accidents.

Therefore, according to the process requirements, the newly-built equipment pipeline needs to use chemical cleaning to remove the oil stains and other impurities on the inner pipe wall before the device is driven. At the same time, the supplier will be required to degrease the pipeline.
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Stainless steel oxygen pipe degreasing cleaning step water rinse

Stainless Steel Oxygen Pipeline Degreasing Cleaning Procedure: Water Flushing → Manual Wipe Degreasing → Water Flushing → Compressed Air (or Nitrogen) Purge.

Water flushing Use a small high-pressure water washing device to flush the pressure during flushing. The pressure is controlled at about 0.6Mpa to ensure that the impurities inside the pipe are flushed. The purpose is to remove ash, sediment, detached metal oxides and other loose dirt from the pipeline.

Manual wiping and degreasing Inject the cleaning degreasing agent into the cleaning basin, add it in proportion, mix it and use it, and wipe it repeatedly. During the cleaning process, the cleanliness of the degreasing cleaning fluid must be monitored. If the color of the degreasing cleaning fluid becomes dirty, the existing degreasing fluid must be drained and the degreasing cleaning fluid must be reconfigured. The purpose is to remove all kinds of organic substances such as oil, graphite, anti-rust oil, etc. in the pipeline, so as to ensure that the pipeline is clean and clean at the time of installation to meet the requirements of equipment operation.

Water Flush After the degreasing of the pipe is completed, rinse with plenty of water. When the flushing water flowing out of the pipe is clean, the water flushing can be completed. The purpose of the degreasing water rinse is to rinse off the defatted raffinate inside the pipe.

Compressed air (or nitrogen) purging purges with oil-free compressed air (or nitrogen), blows the inside of the pipe and cleans the pipes or parts with a clean plastic cloth to ensure the cleanliness of the pipe and avoid Secondary pollution.

Degreasing acceptance method for stainless steel Pipeline degreasing treatment Application of the degreasing solvent specified in the design and requirements of degreasing. If the design is not specified, carbon tetrachloride can be used to degrease and check whether the degreasing is qualified.
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Non-fat stainless steel pipe packaging

After the pipeline is degreasing and cleaned, the following requirements shall be met:
1) Inspect the inner wall of the pipe with ultraviolet light with a wavelength of 320-380 nm. There should be no grease fluorescence.
2) Wipe the inner wall of the pipe with clean, dry white filter paper. There should be no traces of oil on the paper.
3) Or use a degreasing solvent to detect the fat content does not exceed the request of the client.
4) Other relevant technical indicators proposed by the entrusting party.

The stainless steel oxygen pipeline chemical cleaning and degreasing process regulates the oxygen pipeline cleaning and degreasing construction process, greatly improving the internal cleanliness of the oxygen pipeline, and is a reliable guarantee for safe and efficient operation of the oxygen pipeline. It is worthy of attention and promotion by stainless steel pipe manufacturers.

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