What should be the valve configuration when starting a centrifugal pump?

When starting a centrifugal pump, the correct configuration is to have the suction valve open and the discharge valve closed. This setup allows the pump to build up pressure and prime itself effectively.

Having the suction open ensures that the pump can draw in fluid from the source, providing the necessary liquid supply for proper operation. Meanwhile, closing the discharge valve prevents the fluid from exiting the system, allowing the pump to establish a flow and develop the required pressure within the pump casing. This is critical for avoiding a situation where the pump could run dry, which can lead to damage.

Once the pump is properly primed and operating, the discharge valve can be gradually opened to allow flow to the system. Proper valve configuration is essential to ensure safe operation and to protect the pump from damage during startup.