Why cannot hydrogen pipelines be washed with water
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I would like to ask fellow sailors: what is the reason why hydrogen pipelines cannot be washed with water?
It can be considered from aspects such as corrosion, catalysts, and unit operation
After the hydrogen-handling pipelines are washed with water, they are not thoroughly cleaned by blowing with air; to prevent catalyst damage caused by residual water in subsequent steps, the hydrogen-handling systems are generally cleaned using purge blasting
The material of hydrogen-handling pipelines has strict requirements regarding chloride ions in water. Additionally, if the pipelines are washed with water, the water remaining inside them cannot be easily removed, which is detrimental to the catalysts used later on!
What to do for hydraulic testing of pipelines in newly installed units? Is there any alternative method?
Pressure testing can be done using nitrogen; the standards may vary, and nitrogen testing requires a lower pressure level； Water pressure testing is also an option, though it is not recommended. There are processes such as furnace drying at the beginning of operation, and it is sufficient to take care of those matters before loading the catalyst.
Oh, there are furnace drying and hot-state testing before loading the catalyst, and this can be achieved
It can be washed with water, but not ordinary water. When installing the equipment, all pipelines and devices need to be pressurized with water; usually demineralized water is used, mainly to protect the equipment. As a little insight: when our company built its first hydrogenation unit, pure water from large containers was used to pressurize the heating furnace tubes. . . Big barrels of pure water? Haha, that was over 20 years ago; back then, people were worried that impurities in the water might damage the equipment.
Air pressure testing cannot replace water pressure testing. The airtightness and strength are the same