Pump purging

Purging of the unit (there seem to be no specifications for pumps, but there definitely are ones for pipelines). Once the comprehensive inspection of the unit is completed and the project construction has been approved, the workshop should begin the preparatory work prior to starting up the unit. First, a comprehensive and thorough purging of the device’s process pipelines and flow systems is carried out. The purpose of purging is to remove debris such as sediment, slag, and rust remaining in the pipes, thereby preventing valves from getting stuck, pipeline equipment from becoming clogged, and pumps from being damaged. Through purging operations, the quality of pipeline construction can be further inspected to ensure smooth operation of the pipeline equipment and a seamless flow of processes, while also helping operators become more familiar with the operational procedures in order to prepare for commissioning. When purging the hydrogenation unit, the following points should be noted: ① When introducing the purge medium, the pressure applied must not exceed the design pressure. ②Purified air lines, non-purified air lines, nitrogen lines, circulating water lines, fresh water lines, steam lines, etc., shall all be purged using their respective media. ③Cooling exchange equipment and pumps are not included in the purging process; those with bypass lines use those bypass lines, while those without bypass lines have their inlet flanges removed. ④To proceed with the purging according to the standard procedure, first purge the main lines, then the branch lines and the connected pipelines; purging should be carried out in segments as much as possible. ⑤During steam purging, it is essential to first drain the condensate before introducing steam; the introduction of steam must be done slowly to prevent water hammer. When introducing steam into the equipment, vent it at the top and drain condensate at the bottom. After the equipment has been purged, purge each connecting process pipeline from top to bottom. ⑥Purging must be repeated until the pipeline is clean. If necessary, the blasting and purging method can be employed. After purging, it should be completely drained to ensure no water remains in the pipelines.

It is generally required to isolate the pump to prevent debris from entering it and causing equipment failure； Add a filter during water transport.

One of the reasons for not purging the pump or performing a brief purge is that many plants use medium-pressure steam for purging, which has a high temperature (above 200 degrees). High-temperature steam can easily damage the pump as well as the O-rings and gaskets used in the mechanical seal.

In the case of heavy oil pumps, special flushing pipelines are generally installed to use diesel to dilute and flush the heavy oil, thereby preventing freezing when the pump stops operating; for high-temperature pumps, steam purging can be used.

Does an instantaneous increase in the blasting purge flow rate have an impact on the pump? If you know, please help answer. Thank you!