Is there a bypass issue with the pump outlet check valve?
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Why do some pumps have a bypass at their outlet check valve, while others don’t? Can anyone among my colleagues help explain this?
Reply to 1# Summer Hurricane: This is done based on process requirements. Generally, a check valve at the pump outlet does not require a bypass line; however, a bypass line is necessary when the process demands material return or when purging is needed!
Reply to 2# qsczsewdx: Actually, the pre-heating line can also be considered as a bypass for the check valve!
According to the process requirements, if it is necessary for the medium to flow back to the standby pump – for instance, when the ambient temperature is low enough to reach the freezing or crystallization point of the medium, preventing the startup of the standby pump, or when preheating or other measures are required – a bypass line must be installed. Additionally, depending on the properties of the medium, such as its abrasiveness or corrosiveness, and if the outlet valve of the pump is too large or expensive, a bypass line is needed to prevent wear of the sealing surfaces due to prolonged backflow. A bypass line should also be installed on the outlet valve.