What should be done after a centrifugal pump is started with a closed discharge valve?

When a centrifugal pump is started with a closed discharge valve, it is essential to gradually open the discharge valve. This practice is crucial for several reasons.

Initially, starting the pump with a closed discharge valve can cause the pump to develop excessive pressure due to the fluid being unable to exit. This high-pressure condition can lead to damage to the pump bearings, seals, or even the pump casing itself. By gradually opening the discharge valve, the operator allows the system to adjust to the increasing flow rate and pressure more safely. This controlled approach helps to mitigate the shock that would otherwise occur if the valve were opened suddenly, resulting in a sudden surge of fluid and pressure which could be detrimental to the pump and associated piping.

Additionally, this method allows for monitoring and ensuring that the pump is functioning within acceptable parameters. It gives the operator the opportunity to assess the vibration and sound of the pump, confirming that it is running smoothly and efficiently. Overall, gradual opening of the discharge valve contributes to the longevity and reliability of the pump while maintaining system stability.