Purging of gas system pipelines
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This post was last edited by sxf1028102800 on May 13, 2017, at 09:49. During the initial start-up of my gas separation unit and pipeline purging, is it necessary to remove the control valve? Can I simply close the valves on both sides of the control valve instead? At the same time, check whether the pressure gauge valve is also closed, or remove the pressure gauge and blow it with steam. Please share your thoughts, thank you, extra points
To remove the purge, if a thorough cleaning is desired, explosive purging can be employed. Things like pressure gauges, flow meters, and globe valves can be fixed by simply closing them; blow out the main pipes first, then the branch pipes, and finally the instruments.
The initial startup phase involves cleaning away all slag, as well as conducting pressure tests; therefore, everything that could be damaged by the slag must be removed, including safety valves.
All measuring elements must be taken offline; the control valve must also be taken offline. Especially with gate valves, the problem of poor sealing is often caused by using this valve as a control point for purging during the cleaning process, or by residual welding slag and debris in the seal groove due to incomplete cleaning of the upstream pipeline. Therefore, the conditionally equipped gate valves also need to be taken offline; they can be reinstalled only after being thoroughly purged
All of them need to be purged; blind flanges should be installed on all precision instruments
During purging, the control valve must be removed and replaced with a pipe splice. The pressure gauge also needs to be removed.
The control valve is removed, and then the upstream and downstream pipelines are pressurized and blown out separately; this process is repeated several times. A tin sheet is used to block off certain areas while checking the effectiveness of the cleaning process. Even so, some welding slag remains. . .