Problems with pressure testing and purging welded valves
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As the title suggests, what should be done regarding the welding valves on the high-pressure pipelines in the ammonia synthesis system during the purging and pressure testing phases? What needs to be done after the valve has been welded?
The focus of control should be on avoiding the generation of mechanical impurities prior to purging. For example, using methods such as TIG welding for the root pass during welding can help control the formation of large particles of slag. The pipes are pickled and passivated to ensure cleanliness after welding. As for the final purging, it can help avoid damaging the valve ports, for reference.
Argon arc welding is typically used for the first weld, to prevent slag from remaining on the inside of the tube； The second purge and test are to ensure that seals and the like are not damaged. Appropriate measures can be taken according to the instructions for different valves. The test valve for the pipeline is in the fully open position.