First of all: Due to their design, submersible waste water pumps are not suitable for shallow suction.
A brief explanation of how they work and the background:
As with other submersible pumps, an impeller is set in rotation by an electrically powered motor inside the pump. The centrifugal force sucks the water into the pump and discharges it via a hose. Basically, the pump and the connected hose must first be completely filled with water so that water can be pumped.
Due to the laws of physics, experience has shown that at low water heights < 2 cm, it can take several minutes for the water to be pumped.
The reason for this is that at low water levels, the turbine must first suck in the water to fill the turbine chamber of the pump with water. At the same time, the existing air is displaced via a small vent hole. Only when the turbine chamber is completely flooded with water and the connected hose is also filled with water, which can take several minutes depending on the size of the air volume, is water visibly pumped at full pressure.
It would be advantageous if the pump and possibly the hose remained completely filled with water. This means that the air does not have to be removed from the pump first. The water can be pumped directly.
Shallow suction should only ever be carried out in manual mode. Due to the low water level, an interruption during pumping can disrupt the reliable pumping process and ultimately mean that no more water can be pumped. An interruption can cause air to accumulate in the pump again, which must first be removed during the next pumping process. It may not be possible to remove the air from the pump after an interruption so that further pumping is no longer possible.
Using a smaller hose diameter, for example a ½" hose, can be helpful for small amounts of water. When using a ½" hose, make sure to keep the hose as short as possible. We recommend a maximum length of 5m for a ½" hose.
For shallow suction in rooms, a minimum flow rate is highly recommended, as the lower the water level, the water may not be able to flow quickly enough and air may be sucked in more quickly as a result. This in turn would cause the flow to stop and the process would have to be started again from the beginning.
Please bear in mind that a possibly spring-loaded non-return valve in conjunction with an existing water column (delivery head) in the hose, which also presses on the flap of the non-return valve, can cause too much resistance for the pressure generated by the pump. This is particularly critical for shallow suction of low water levels, as the pump is not able to generate the necessary pressure to open the non-return valve due to possible air cushions in the turbine area.
By removing the non-return valve in the pump outlet, the time until pumping starts can be considerably reduced.
For this reason, avoid delivery heights of over 2 m during shallow suction.
A brief explanation of how they work and the background:
As with other submersible pumps, an impeller is set in rotation by an electrically powered motor inside the pump. The centrifugal force sucks the water into the pump and discharges it via a hose. Basically, the pump and the connected hose must first be completely filled with water so that water can be pumped.
Due to the laws of physics, experience has shown that at low water heights < 2 cm, it can take several minutes for the water to be pumped.
The reason for this is that at low water levels, the turbine must first suck in the water to fill the turbine chamber of the pump with water. At the same time, the existing air is displaced via a small vent hole. Only when the turbine chamber is completely flooded with water and the connected hose is also filled with water, which can take several minutes depending on the size of the air volume, is water visibly pumped at full pressure.
It would be advantageous if the pump and possibly the hose remained completely filled with water. This means that the air does not have to be removed from the pump first. The water can be pumped directly.
Shallow suction should only ever be carried out in manual mode. Due to the low water level, an interruption during pumping can disrupt the reliable pumping process and ultimately mean that no more water can be pumped. An interruption can cause air to accumulate in the pump again, which must first be removed during the next pumping process. It may not be possible to remove the air from the pump after an interruption so that further pumping is no longer possible.
Using a smaller hose diameter, for example a ½" hose, can be helpful for small amounts of water. When using a ½" hose, make sure to keep the hose as short as possible. We recommend a maximum length of 5m for a ½" hose.
For shallow suction in rooms, a minimum flow rate is highly recommended, as the lower the water level, the water may not be able to flow quickly enough and air may be sucked in more quickly as a result. This in turn would cause the flow to stop and the process would have to be started again from the beginning.
Please bear in mind that a possibly spring-loaded non-return valve in conjunction with an existing water column (delivery head) in the hose, which also presses on the flap of the non-return valve, can cause too much resistance for the pressure generated by the pump. This is particularly critical for shallow suction of low water levels, as the pump is not able to generate the necessary pressure to open the non-return valve due to possible air cushions in the turbine area.
By removing the non-return valve in the pump outlet, the time until pumping starts can be considerably reduced.
For this reason, avoid delivery heights of over 2 m during shallow suction.