How to install water pump inlet and outlet pipes?
When the water pump outlet pipe is installed, the variable diameter pipe should be concentric variable diameter pipe, and a flexible rubber hose joint should be connected at the pump port to reduce the vibration force transmitted to the pipeline due to the pump vibration, and the pressure gauge should be installed on the short pipe in front of the valve, and the check valve and gate valve (or stop valve) should be set on the outlet pipe. The function of the check valve is to prevent the water of the outlet pipe from flowing back to the pump and impacting the impeller after the pump stops. Water inlet pipe installation scheme is similar to: self-priming pump water inlet pipe installation is the most important part affecting the suction range of self-priming pump, installation is not good leakage, pipeline is too long, too thick, too small, the number of elbow and elbow degree will directly affect the self-priming pump suction water. 1, large mouth self-priming pump with small water pipe water supply many people think that this can improve the actual head of the self-priming pump, the actual head of the self-priming centrifugal pump = total head ~ loss of head. When the pump type is determined, the total head is certain; The loss of head is important from the pipeline resistance, the smaller the pipe diameter, the greater the resistance, so the greater the loss of head, so reduce the diameter, the actual head of the centrifugal pump can not increase, but will decrease, resulting in the self-priming pump efficiency drop. Similarly, when the small diameter water pump uses the large water pipe to pump water, it will not reduce the actual head of the pump, but will reduce the loss of head due to the reduction of pipeline resistance, so that the actual head is improved. There are also machines that think that when the small diameter water pump pumps with large water pipes, it will greatly increase the motor load. They think that the diameter of the pipe increases, the water in the water outlet pipe will exert great pressure on the pump impeller, so it will greatly increase the motor load. As everyone knows, the size of the liquid pressure is only related to the height of the head, and has nothing to do with the size of the pipe cross-sectional area. As long as the head is certain, the impeller size of the self-priming pump is unchanged, no matter how big the diameter of the pipe, the pressure acting on the impeller is certain. However, with the increase of pipe diameter, the flow resistance will be reduced, and the flow rate will be increased, and the power cost will be increased appropriately. But as long as in the rated head category, no matter how to increase the diameter of the pump can work normally, and can also reduce the pipeline loss, improve the efficiency of the pump. 2. When installing the self-priming pump water inlet pipe, the degree of degree or upward warping will make the air collected in the inlet pipe, the vacuum of the water pipe and the centrifugal pump, so that the suction head of the centrifugal pump decreases and the water output decreases. Accurate approach is: the degree of the section should be slightly inclined to the direction of the water source, should not be degree, more not to tilt up. 3. If more elbows are used on the water inlet pipe of self-priming pump, local water flow resistance will be increased. And the elbow should turn in the vertical direction, do not agree to turn in the degree direction, so as not to collect air. 4, the self-priming pump inlet is directly connected with the elbow, which will make the water flow through the elbow into the impeller uneven distribution. When the inlet pipe diameter is larger than the water pump inlet, eccentric reducer pipe should be installed. The flat part of the eccentric reducer should be installed on the top, and the inclined part should be installed on the bottom. Otherwise, collect air, reduce the amount of water or pump water, and have a crash sound. If the diameter of the water inlet pipe is the same as that of the water inlet of the pump, a straight pipe should be added between the water inlet and the elbow. The length of the straight pipe should not be less than 2 to 3 times the diameter of the water pipe. 5, the self-priming pump is equipped with the bottom valve of the water inlet pipe next section is not vertical, such as this installation, the valve can not be closed by itself, causing water leakage. The exact installation method is: equipped with the bottom valve of the water inlet pipe, the next section is best vertical. If vertical installation is not possible due to terrain conditions, the Angle between the pipe axis and the degree plane should be above 60°. 6. The inlet position of the self-priming pump water inlet pipe is not correct. (1) The distance between the inlet of the self-priming pump water inlet pipe and the bottom and wall of the water inlet pipe is less than the diameter of the inlet. If there is sediment and other dirt on the bottom of the pool, the interval between the inlet and the bottom of the pool is less than 1.5 times the diameter, it will cause the water intake is not smooth when pumping or suction sediment and debris, blocking the inlet. (2) When the water inlet depth of the water inlet pipe is not enough, it will cause the water surface around the water inlet pipe to produce whirlpools, affecting the water intake and reducing the water output. The accurate installation method is: the water inlet depth of small and medium-sized water pump shall not be less than 300 ~ 600mm, and the large water pump shall not be less than 600 ~ 1000mm7. The outlet of sewage pump is above the normal water level of the outlet pool. If the outlet of sewage pump is above the normal water level of the outlet pool, although the pump head is increased, the flow is reduced. If the water outlet must be higher than the water level of the outlet pool due to the terrain conditions, elbow and short pipe should be installed in the pipe mouth, so that the pipe becomes a siphon and the height of the outlet can be lowered. 8. Self-priming sewage pump with high head works in low head. Many customers usually think that the lower the head of centrifugal pump is, the smaller the motor load is. In fact, for the sewage pump, when the sewage pump model is determined, the size of the power consumption is proportional to the actual flow of the sewage pump. The flow of the sewage pump will decrease with the increase of the head, so the higher the head, the smaller the flow, the smaller the power consumption. On the contrary, the lower the head, the greater the flow, the greater the power consumption. Therefore, in order to prevent motor overload, it is generally required that the actual pumping head of the pump should not be less than 60% of the calibrated head. So when the high head is used for too low head pumping, the motor is easy to overload and heat, serious can burn the motor. In case of emergency use, it is necessary to install a gate valve for regulating the water outlet in the outlet pipe (or block the small outlet with wood and other things) to reduce the flow rate and prevent motor overload. Pay attention to the temperature rise of the motor. If the motor is found to be overheated, turn down the water outlet flow or shut it down in time. This point is also easy to misunderstanding, some operators think that plugging the water outlet, forcing the reduction of flow, will increase the motor load. In fact, on the contrary, the outlet pipe of regular high-power centrifugal pump drainage and irrigation units is equipped with gate valves. In order to reduce the motor load when the unit starts, the gate valve should be closed first, and then gradually opened after the motor starts. This is the reason.
