After repairing a leak in a tube containing concentrated nitric acid, how should the concentrated nitric acid inside the tube be removed?
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After repairing a leak in a tube containing concentrated nitric acid, how should the concentrated nitric acid inside the tube be removed? Should it be blown by air or allowed to flow naturally?
It can be purged with nitrogen; proper protection must be in place to prevent injuries
For the pumping equipment, divert the material inside the pipeline through a bypass line to ensure that no acid flows through the pipeline that is to be repaired. The remaining acid is directed to a storage tank or recovery tank via the valves in the system. The pipeline is purged using compressed air; if there are valves with flow stagnation, open and close them several times to see if it’s possible to control such stagnation. If the stagnation is severe, the only option is to shut down the system, replace the valve, and then carry out the repairs
Gravity flow is relatively safe; if that doesn’t work, use purging.
Is the stagnation due to the valve not being closed properly, with flow still existing in the pipeline?