What happens when air enters the pump? (Consequences)
The presence of air will interfere with the normal water inlet process of the water pump, resulting in insufficient water inflow, which will cause uneven and fluctuating water flow. This unstable water flow will directly affect the stability of water pressure, causing the centrifugal pumps to be unable to maintain optimal working conditions during operation, thereby significantly reducing the overall operating efficiency of the water pump and possibly increasing energy consumption and equipment wear.
Increased noise from the water pump: The presence of air inside the water pump can easily cause water flow imbalance and vibration. When the water pump is working, the noise will increase significantly, affecting the comfort of the use environment.
Shortened service life of the water pump: The air in the pump body will impact and wear the impeller and bearings of the water pump, thereby reducing the service life of the water pump, requiring frequent replacement of wearing parts, and increasing maintenance costs.
Impact on water quality: The presence of air at the pump inlet and in the pipe system will cause gas stagnation in the water flow, which can easily lead to the accumulation of sediment and corrosion of the metal surface. These precipitation and corrosion phenomena will not only destroy the structural integrity of the pipe, but also pollute the water quality, increase the impurity content in the water, and further affect the cleanliness and sanitation standards of the water quality, which may have an adverse effect on the overall operation of the system and the safety of water resources. Therefore, it will be more reassuring to choose a stainless steel vertical pump in daily life.
Why does air enter the pump body? (Reason)
Centrifugal pumps are usually divided into vertical multistage centrifugal pumps and horizontal multistage centrifugal pumps. Both types of water pumps may cause air to enter due to common reasons such as poor sealing, pipeline leakage, and failure to fill the pump with water before starting. However, due to their different structures and installation methods, the specific air entry paths may be different:
Vertical pumps can usually meet the needs of large projects in various industries because of their large motor power. They are usually installed at a higher position, which may cause air to easily accumulate in the upper part of the pump body, especially after the pump is started or stopped. If the suction stroke of the pump is too high or the suction pipe fails to keep full of water, air is more likely to enter the pump body through the pipe. The suction pipe of the vertical pump is usually arranged vertically. If the water column in the pipe is unstable or there is a gap, a vacuum may be formed, causing air to enter through the pipe joint or poor sealing.
Horizontal pumps are usually suitable for home, apartment water supply, or small project assembly due to their smaller size. They are usually installed at a lower position, and the suction pipe is mostly arranged horizontally. If there is a long horizontal section in the suction pipe, the water flow in the pipe slows down, bubbles may form locally, and air is easy to accumulate and enter the pump body. If the water suction port is installed in an improper position and is too far below the liquid level, it may cause eddy currents in the liquid during flow, thereby drawing in air.
However, there are usually several common reasons for air entering the centrifugal pump:
1. The water pump inlet pipeline is not well sealed, and the "O" ring in the shaft sleeve is damaged, causing water leakage.
2. The pump bottom valve is damaged, causing the pump to be in a leaking state for a long time.
3. The screws on the pump inlet pipe are not tightened, causing air to enter the pump body.
4. The sealing surfaces of the water pump inlet flange and outlet flange are defective, affecting the sealing of the pump body.
5. The pump body itself is excessively worn due to packing, causing air to enter the cavity.
6. The water pump inlet flange and the pump flange form a cone angle, which affects the sealing and causes air to enter the pump cavity.
7. The middle sealing surface of the water pump is not clean, causing damage to the sealing gasket and leakage of the water inlet hole.
8. After the pump has been running for a period of time, sand holes, air holes and other phenomena will appear in the castings of the pump parts themselves.
What to do when air enters the pump body? (Solution)
First, we need to exhaust the air in the centrifugal pumps. After exhausting, we will check the reason why the pump body has air in it. If there is no problem (such as the first operation of the pump), it can be restarted; if the screening shows a leak, it must be repaired before restarting.
The following are several common exhaust methods we use:
1. Automatic exhaust of the pump body: Some water pumps are designed with a gas return chamber or exhaust valve. When the water pump is started, the gas will enter the pump along with the water, and then be discharged through the gas return chamber or exhaust valve.
2. Manual exhaust: If the water pump does not have an automatic exhaust device, you can try to exhaust it manually. First, close the outlet valve of the pump, then open the water inlet valve, and let the water flow freely into the pump body to continuously remove the air.
3. With the help of the exhaust valve: Some water pumps will be equipped with a special exhaust valve for exhaust. First open the exhaust valve, then gently turn on the outlet valve, and close the exhaust valve after the gas is exhausted to smoothly exhaust the air from the pump body.
4. Use a vacuum pump: When installing and using the centrifugal pumps for the first time, you can use a vacuum pump to exhaust. First, connect the vacuum pump to the outlet pipe of the water pump, then turn on the vacuum pump to extract the air in the pump through negative pressure.
If you have a better solution to deal with the problem of air entering the centrifugal pump, we welcome you to communicate with us and work together to improve the solution; or if you encounter any problems during the use of the water pump, you can consult us at any time.(Clink here)