Troubles with hot work? Seeking help from all the experts here
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What are the measures for hot cutting operations in closed sewage pipes? The hydrogen sulfide levels are 200, CO is at 40, and COMB is also at 40; an alarm is triggered due to these high levels. There are no flanges in the middle of the pipeline, so it’s not possible to clean or replace it. What should be done by installing a blind flange?
How about first performing a water wash and nitrogen purging, and then cutting?
Filled with water； After draining the water from the highest point ； Add clean water again before starting the fire ； Or purge with steam before performing hot work
Flush with water; find a flange upstream that can be sealed and install a blind plate. Flushing several times with water or steam will suffice~~~~
The problem is that there isn’t a single flange anywhere along the several hundred meters of pipeline; the only flange located in a lower area is constantly filled with water, making it impossible to get anything inside
Could you tell me from which location the testing was carried out? Why was it necessary to cut the pipes?
It seems like your question isn’t clear enough. Why can’t water be poured in from the flange at the lower level? ? Is it blocked? Working on long-distance pipelines involving open flames is no joke; moreover, you haven’t cut the flange connections yet, and things could explode if anything goes wrong! If it’s really necessary to use fire, then do so; otherwise, create an opening first, fill it with water, and then proceed
Why is welding needed? Can’t we use other methods?
It’s not possible to use physical methods to seal off the pipeline; wait until the treatment is completed before proceeding with any work involving fire. If you can take samples, it means there’s a way to access the pipeline, and nitrogen can be used to displace the gas there. Moreover, for long pipelines, samples need to be taken at various sections. With such high levels of hydrogen sulfide, working in such conditions is unsafe, and accidents are likely to occur
That’s right; it’s already been done. The company, in an effort to save money, doesn’t use flanges, and things will get even worse in the future