1、 The leakage of the seal ring is lost at the inlet of the impeller. A seal ring is provided. During the operation of the water pump, because there is a pressure difference on both sides of the seal ring, one side is approximately the outlet pressure of the impeller, and the other side is the inlet pressure of the impeller, there will always be some liquid leakage from the outlet of the impeller to the inlet of the impeller. Some of the liquid gets energy in the impeller, but the liquid is not sent out, which reduces the water supply of the pump. The energy of leaking liquid is used to overcome the resistance of sealing ring.? Obviously, the larger the seal ring diameter Dw is, the greater the pressure difference between its two sides is, and the greater the leakage is. With regard to the finalized water pump, in order to reduce the leakage and improve the power of the water pump, the clearance of the sealing ring should be reduced when allowed.

Generally, the total clearance is approximately 0.002 of the seal ring diameter. If Dw=200mm, the total clearance is 0.40mm. During installation, the sealing ring shall not be too biased, otherwise, the leakage will also be increased. In addition, the leakage can be reduced by adding the resistance of the seal ring. The first way to add the resistance is to make the seal ring into a labyrinth, zigzag, etc. This also adds the seal length of the seal ring, increasing the resistance along the way. The leakage of the seal ring will lead to the disturbance of the impeller inlet in some cases, so it is necessary to plan the seal ring mode reasonably.

2、 Balance tissue leakage loss? In many centrifugal pumps, there are organizations to balance the axial thrust, such as balance holes, balance pipes, balance plates, etc. Because there is a pressure difference on both sides of the balance organization, some liquid also leaks from the high-pressure area to the low-pressure area (official account: pump manager). The leakage of the balance hole will reduce the power of the water pump by 5%. In the balance plate organization, the leakage amount accounts for 3% of the operating flow, but some high-pressure pumps are larger than this value; In order to reduce leakage loss, the diameter D 'of the balance disc can be reduced without affecting the balance force.

3、 Loss of interstage leakage? In a volute type multi-stage pump, the pressure on both sides of the interstage diaphragm is not equal, so there is also leakage loss. According to the different organizational arrangements, the pressure difference on both sides of the interstage diaphragm may be one stage, two stage or three stage. The more the stage difference is, the more serious the interstage leakage of the diaphragm is. Therefore, stepped interstage seals are widely used here.? In addition, interstage leakage also exists in segmented multistage pumps.