Start the centrifugal pump and open the outlet valve

Whether the outlet valve needs to be opened or closed when starting a centrifugal pump depends mainly on the pump’s characteristics, system requirements, and starting conditions. Below is a brief explanation of the advantages and disadvantages of the two scenarios: 1. **Starting by opening the outlet valve**: - **Advantages**: The pump experiences less load during startup, as water in the system can flow, which helps reduce the current required to start the motor as well as the mechanical stress on the pump. This method helps to protect the pump and motor, and is particularly suitable for large pumps or situations where there are restrictions on the starting current. - **Disadvantage: If the system design is inadequate, opening the outlet valve during startup may lead to unstable flow and pressure control, especially before the pump reaches its normal operating condition. 2. **Start by closing the outlet valve**: - **Advantages**: This method prevents fluid flow in the system when the pump starts, which helps to establish system pressure more quickly. Once the pump reaches a stable operating state, gradually opening the outlet valve allows for better control of the system’s pressure and flow, thereby preventing shock pressures from being applied to the pipes and valves. - **Disadvantage**: The pump and motor are subjected to high loads at startup, as they need to overcome the static system pressure. This can result in high motor starting currents, increasing mechanical wear and thus having an impact on the equipment’s lifespan, especially in situations where the equipment starts and stops frequently. Which method to choose depends on the specific application scenario and system design. For example, for applications that require rapid establishment of system pressure at startup, it may be chosen to start with the outlet valve closed. In situations where it is necessary to protect the equipment and reduce current surges during startup, it may be advisable to start by opening the outlet valve. .

This “some” had better be made clear. The characteristic of a centrifugal pump is that starting with the outlet valve fully closed results in the lowest starting current.

Centrifugal pumps generally require the outlet valve to be slightly opened before starting the pump, to ensure that the liquid inside the pump can flow. Reduce the internal load on the pump; after the pump is operating stably, adjust the opening degree of the outlet valve according to the required operating conditions.

The centrifugal pump is started with the outlet valve closed, which reduces the starting current and prevents a drop in grid voltage caused by pump startup, thus avoiding disruptions.