Centrifugal pump outlet valve: XL inertia opening of 1/5, or 1/6, 1/7, or smaller

A small opening of the centrifugal pump’s outlet valve can lead to the following hazards: 1. It increases the workload on the pump, placing greater stress on the motor and resulting in higher power consumption. 2. It may cause cavitation inside the pump, thereby affecting its lifespan and efficiency. 3. Due to low flow rate, the fluid velocity inside the pipeline slows down, which may lead to blockages in the pipeline. Relatively speaking, the advantages of a low opening degree may include: 1. It is possible to make adjustments when the system does not require full capacity for transportation, thereby achieving energy savings. 2. Reduce the impact pressure on pipes and equipment, thereby extending their service life. Personally, I believe setting the pump outlet valve opening too low is not the best approach. Unless there is a specific need to regulate the flow rate, the valve opening should be adjusted appropriately based on the pump’s design parameters and the actual requirements of the system, in order to ensure the efficient operation of the pump and the stability of the system. The risks and increased costs associated with too small an opening usually outweigh the benefits of energy savings. .

The pump will overheat if it runs for a long time, and the mechanical seal is prone to damage; nothing else really, it just consumes more electricity, but the motor won’t burn out

First, to start a centrifugal pump, the inlet valve must be fully opened while the outlet valve is closed in order to minimize the starting load. This approach demonstrates that the smaller the opening degree of the outlet valve, the lower the energy consumption. Generally, it is necessary to maintain the pressure before the outlet valve of the centrifugal pump at the specified level, that is, the pump’s rated pressure (head), and the opening degree of the outlet valve is used to control the flow rate required. But the adjustment must be made under the condition that it is not less than the pump’s rated pressure. As for the hazards associated with the opening degree of the outlet valve, if it is too small, it will cause the temperature of the fluid inside the pump to rise; in severe cases, this can lead to the vaporization of the liquid, as well as changes in the structure of the machine components, which can damage the pump. As for the disadvantages of a smaller valve opening, it is beneficial for saving electrical energy as long as the temperature of the fluid medium does not rise. For reference.

It indicates that choosing a pump with excessive performance brings more disadvantages than advantages; the impeller diameter can be appropriately modified to be smaller

With such a small valve opening, the pump will overheat if it operates for a long time; the liquid medium inside the pump is prone to vaporization, which can also lead to damage to the sealing components. If replacing the pump is not an option, it is recommended to add a return line from the tank in order to maintain an appropriate opening for the outlet valve – this will, however, result in higher electricity consumption.

I’ve learned that valves can easily lead to poor sealing, and it’s frustrating when dealing with flammable and explosive substances during maintenance