Why isn’t the pump body included in the purging?
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When purging the pipeline that passes through the pump, it is necessary to first purge in the direction opposite to the flow of fluid through the pump, and then remove the cover of the pump’s inlet filter to purge the inlet pipeline; the pump itself is not involved in this purging process. Why?
Piping purging is generally carried out only after the plant is started up for the first time or following a major overhaul. In my opinion, the reasons why the pump itself needs to be involved in the purging process are as follows: 1. During piping purging, gas flows within the pipes, which can cause the pump to run idle. Some pumps must not run idle, as this can damage the seal or bearings (the bearings in magnetic pumps)； 2 During the purging process, iron shavings in the pipes are likely to enter the bearings of the pump (magnetic pump), the seal faces, the mouth rings, etc., causing severe damage to the pump ；
What was said on the 2nd floor is correct. During one of our maintenance tasks, when cleaning the pipelines, we brought residual styrene into the pump, which caused the impeller to get clogged by styrene polymers; as a result, the pump had to be disassembled for cleaning.
Not only the pump, but also the heat exchanger should be bypassed, and the relevant instrument measuring elements should also be removed first.
Before the pump arrives at the site, the manufacturer has already cleaned the pump body; all that is needed is to clean the inlet pipes of the pump. If the pump is included in the purging process, solid debris can accumulate within the pump body, thereby causing it to get clogged. Therefore, it is necessary to isolate the pump body.
Pump purging can cause damage to the pump’s seal
The pump was overhauled separately; the impurities inside it have been removed, so no purging is required.