Purging plan for chemical processing units

The purging plan essentially consists of the principles and precautions for purging, followed by a detailed description of the purging process； The purging principle is roughly as follows: Steam and the pipeline to be purged are used to remove any condensate, thereby preventing water hammer ； For the cold exchange equipment, purge one side while venting the other to avoid pressure buildup ； Remove delicate instrument valves (such as pressure and flow meters, orifice plates, mass flow meters, control valves, safety valves, etc.) to prevent weld slag from entering the valve body and damaging the valves or instruments ； The pump is connected to a bypass line to prevent damage to the mechanical seal ； For cold exchange equipment, use the bypass line first and then purge the equipment itself ； During the purging process, closely monitor the pressure at various points to prevent equipment damage caused by overpressure or backpressure resulting from condensation ； During purging, the steam flow rate should be increased gradually and slowly to prevent damage to pipeline equipment caused by sudden temperature rises ； Control the steam consumption and the pressure in the steam main to prevent low steam pressure caused by an excessive number of purge points, which would result in poor purge efficiency ； Large-diameter pipes require blasting and target cleaning for purging ； The purge control of the distillation tower regulates the steam flow to prevent the trays from being overturned ； Vent at high points, drain at low points – leave no dead corners ； Equipment that is sensitive to water (such as equipment equipped with catalysts, adsorbents, desiccants, desulfurizers, etc.) must be disconnected from the purging system to prevent steam from entering..... Friends who are familiar with this process, please add more details.

This depends on the pipeline and the medium

First be in charge, then just handle it； Segmented purging is used, and the next step is only taken after it is successful ； Blowing out the equipment is strictly prohibited before it is qualified ； For some sophisticated instruments, the valves need to be removed and replaced with bypasses ； Blow-down using blasting method was employed, and the target testing passed ； Ensure proper safety isolation at the discharge outlet.