1, the characteristics of the medium: the name of the medium, specific gravity, viscosity, corrosive, toxic, etc
2, medium contained in the diameter of the solid particles, the content (the mass or volume percentage)
3, medium temperature (℃)
4, need traffic
General industrial pump can be ignored in the process of pipeline system leakage, but affected by the change of flow must be considered. Agricultural use if it is determined by open channel water must also consider leakage and evaporation.
5, pressure, suction pressure exhaust the pool of pressure piping system pressure drop (head losses)
6, pipeline system data (diameter, length, types and number of suction piping fittings to pressure the pool geometry level, etc.) should also be made if necessary device characteristic curve in design layout piping should be paid attention to the following items:
A, reasonable choose pipe diameter pipe diameter under the same flow rate, flow velocity small resistance loss but high price pipe diameter moment lead to resistance losses increase sharply increase the selected pump lift installed with power increasing cost and operation cost are so from the perspective of technical and economic comprehensive consideration
B, discharge pipe and pipe joints should be considered are the biggest pressure
C, pipeline layout should decorate straight pipe to reduce as far as possible in the attachment and try to narrow the pipe length must turn the elbow bend radius should be 3 ~ 5 times the diameter of the pipe Angle is greater than 90 ℃ as much as possible
D, the discharge side of the pump must be installed with the valve (ball valve or valve, etc.) and check valve is used to adjust the point check valve of the pump valve when the fluid flow reversal can prevent reversal and pump to avoid water hammer blow (when liquid backflow produce huge pressure to reverse damage to the pump)
Second, determine the flow head
The determination of traffic
A, if the production process has given the smallest, normal and maximum flow should be taken into account by the maximum flow
B, if only in the production process should be considered normal flux left a certain margin For ns > 100 low flow the unpreparedness lift pump flow take 5% allowance for ns > 50 small flow high lift pump flow allowance take 50 or less 10% ns 100 pump flow allowance also take 5% or less of inferior quality and running conditions of the pump flow allowance shall be 10%
C, if the basic data only to weight rate should be converted to volume flow
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