Steam pipeline purging issues
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Why must steam be used for purging steam pipes? What factors need to be considered during this process? If it’s just about removing slag and other debris from inside the pipes, it doesn’t seem necessary to use steam for cleaning; compressed air can achieve the same result, right? I’m not sure yet if there are any other considerations
This post was last edited by ylb913 on 2015-7-3 06:56. Not only steam pipelines, but most pipelines are purged with steam. For shutting down the entire unit, including the steam vessels and for line cleaning, steam is the primary medium used; therefore, there are formal process pipelines available everywhere for steam, making its use convenient. For steam pipes, those that require target testing also need temperature-controlled purging: heating, purging, cooling, heating, purging... The process of purging with steam also serves to test the thermal expansion and thermal compensation of the piping.
Steam pipelines are purged with steam, which allows for the detection of issues such as thermal expansion of the pipes and sliding of supports. When steam-purged pipelines are expanded and then cooled, the oxide scale inside them tends to fall off and be blown out. The force used in steam purging is substantial; steam purging is necessary for non-thermal pipelines, and the design must take into account the issue of supports, otherwise the pipes are prone to deformation and slipping
The second point is crucial. One more thing to add: the steam flow rate is high. It cannot be replaced by compressed air.
Compressed gas can be stored in tanks for continuous purging
The main focus is on verifying the pipe’s thermal expansion capacity and the condition of the pipe supports
The high-pressure steam pipes that supply steam to the turbine on-site need to be blown with steam for a whole cycle; it’s extremely noisy.
It mainly makes use of the heat from steam, as well as the principle of thermal expansion and contraction, to clean away debris more effectively