[Q&A Question 175] 10.12.2016
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【Q&A Question 175】October 12, 2016: What are the steps for purging light hydrocarbon pipelines? The answer key will be available after responding; scoring is based on answering the key points. Answer: Flush the pipeline through the water flushing line on the light hydrocarbons pipeline, then introduce nitrogen for purging. After purging for a while, open the drain to check if it is clean; finally, introduce steam for purging to ensure that ferrous sulfide formed due to corrosion in the light hydrocarbons pipeline is completely removed. Sponsoring opportunities available for the “2016 HaiChuan Top 10 Members Selection Contest” – http://bbs.hcbbs.com/thread-1628108-1-1.html (Source: HaiChuan Chemical Forum)
Power off, isolate, relieve pressure, ventilate, purge and replace, conduct testing
1. Confirm that there is no pressure in the pipeline. 2. For safety reasons, it is advisable to purge the pipeline with nitrogen first. 3. If hot work is to be carried out on the pipeline, it should be purged with steam. 4. It is strictly prohibited to use air for purging, as this may lead to dangerous situations due to excessive flow speeds. 5. Where possible, closed-system discharge should be used
First, use water to push the oil out, and then use steam to clean the lines
Purging and pressure testing preparation； Install temporary blind plates and remove safety valves and instrumentation, etc ； Configure temporary pipeline ； Strength test ； Reset of safety valves, instruments, etc.; pipeline purging ； Reset the pipeline, remove temporary blind flanges, and install proper gaskets ； Joint inspection
Shreir’s corrosion is the best!
The pipeline is flushed through the water flushing line on the light hydrocarbons pipeline, followed by purging with nitrogen. After a certain period of purging, the drain valve is opened to check whether the pipeline is clean; finally, steam is used for purging to ensure that all ferrous sulfide formed as a result of corrosion within the light hydrocarbons pipeline is completely removed.
Remove all residual materials; use water and nitrogen to purge the flare system, controlling the amount of nitrogen used for purging
Pipeline isolation, nitrogen purging, steam purging, air drying