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The boiler water replenishing pump is adjusted by the unit load, steam flow and other thermal parameters. Its working principle is the same as the ground centrifugal pump. When the motor drives the impeller on the shaft to rotate at high speed, the liquid filled in the impeller moves from the center of the impeller along the blades under the action of centrifugal force. The flow channel between them is thrown around the impeller. Because the liquid is affected by the blades, the pressure and speed increase at the same time. It passes through the flow channel of the guide shell and is directed to the next-level impeller. In this way, it flows through all the impellers and guide shells one after another, further increasing the pressure energy of the liquid. After each impeller is stacked step by step, a certain lift is obtained to lift the liquid to the ground. This is the working principle of the boiler water make-up pump. Boiler feed water pumps are mainly divided into two series: vertical boiler feed water pumps and horizontal boiler feed water pumps. In addition to the difference in structural form, another difference between them is that the vertical boiler feed water pumps are made of stamped stainless steel. The horizontal multi-stage boiler feed water pumps are the earliest generation of boiler feed water pumps. The product material is only made of cast iron, and the sealing form used is a packing seal that may cause dripping. These two series of feed water pumps are mainly used for boiler water supply, so they are called multi-stage boiler feed water pumps. To analyze the reason why a boiler water replenishing pump cannot replenish water, we must consider the entire system in which it is located and eliminate them one by one. Let's take a look at the situation and reasons why the boiler replenishing pump cannot replenish water, cannot pump water, and cannot discharge water. 1. The suction lift is too large. Some water sources are deep, and the peripheral terrain of some water sources is relatively flat. The allowable suction lift of the water pump is ignored, resulting in little or no water absorption. It is important to know that the degree of vacuum that can be established at the suction port of the water pump is limited. The suction distance during vacuum is about 10 meters of water column height, and it is impossible for the water pump to establish a vacuum. Moreover, if the vacuum is too large, it is easy to vaporize the water in the water pump, which is detrimental to the work of the water pump. Therefore, each boiler feed water pump has its maximum allowable suction lift, which is generally between 3 and 8.5 meters. When installing the water pump, do not just consider convenience and simplicity. 2. The resistance loss in the inlet and outlet pipes of water flow is too large. Some users have measured that although the vertical distance from the reservoir or water tower to the water surface is slightly less than the water pump head, the water capacity is still small or cannot be lifted. The reason is often that the pipeline is too long, the water pipe has many bends, and the resistance loss of water flow in the pipeline is too large. The reason is often that the pipeline is too long, the water pipe has many bends, and the resistance loss of water flow in the pipeline is too large. Generally speaking, a 90-degree bend has greater resistance than a 120-degree bend. The lift loss for each 90-degree bend is about 0.5 to 1 meter. The resistance of every 20 meters of pipe can cause a lift loss of about 1 meter. In addition, some users also choose the diameter of the inlet and outlet pipes of the water pump at will, which also has a certain impact on the head. 3. Reasons for no water supply during use 1) Check whether the valve at the boiler water pump inlet is open. If not, please open it. Is there water at the inlet? Is it blocked by foreign matter? If there is no water, it means that the water tank is missing. Replenishing water can solve the problem. 2) When starting up for the first time, the boiler water pump needs to be drained. 3) Check whether it is reversed. If the water pump cannot pump water when it is reversed, you can adjust the boiler water pump to rotate forward (clockwise to forward). If it is controlled by a frequency converter, check manually and automatically respectively. 4) Check whether the outlet pipe of the boiler water pump is blocked. 5) If the above is normal, then take a look at the head on the nameplate of the boiler water pump. If there is water coming out, but the pressure cannot be reached, please close the outlet main valve first, start the boiler water pump, and see if the pressure can reach or exceed the set pressure, and try one by one. If the set pressure can be reached or exceeded, start N-1 pumps (N is the number of main water pumps), slowly open the main valve, and stop rotating when the pressure is equal to the pressure on the nameplate. If the flow rate is not enough for users at this time, then the flow rate of the boiler water pump is small, and it is necessary to increase the water pump or replace it with a high-flow water pump. 6) If the pressure still cannot rise after closing the main valve of the boiler water pump, disassemble the boiler water pump and check whether the impeller in the boiler water pump body is detached or damaged. If so, please replace it. 7) If it is not the above reasons, please confirm that your boiler water pump can achieve the designed flow and head.