Pump when picking type needs to have two very important parameters: one is the traffic; One is the head. Flow only need according to actual working condition to determine how much traffic, controllable scope is bigger, is easy to control. Relatively than the traffic, the head is relatively complex, high lift, power energy saving, small head, water was not up. So make sure good lift is the pump selection a key. To determine the pump head is mainly manifested in the following several aspects: 1, first of all, according to the medium density and viscosity calculation of shaft power, ensure the pump is running will not exceed current. 2, determine the medium, and then according to the actual working condition, divided into local resistance and frictional resistance calculation. Local resistance is by piping fittings (elbow, tee, valve, etc.), it draw resistance coefficient, dynamic pressure is proportional to the. Bureau drag coefficient can be categories according to the attachment, the opening size through manual check, is proportional to the square of the dynamic pressure and velocity. 3, frictional resistance is better than friction multiplied by the length of pipe, than friction by the diameter of pipe wall roughness, determine the fluid velocity, finally concluded that the head loss in operation. 4, and finally determine the pump transmission medium from water to water the relative vertical elevation difference, it is concluded that vertical lift, plus the head loss, it is concluded that the final actual pump head. 5, in the end, the make and model of the pump can be selected according to the flow and head according to the medium can choose the material of pump, and then determine the motor power, choose the pump specific models.
