Pump Selection according to the specific circumstances of concrete analysis, the main consideration pump flow and pump head. Its method is as follows:
(1) The pump is selected to determine the flow rate:
Flow rate = (total water + channels Farmland water loss) / pump operating time
Total agricultural water demand is difficult to generalize, to be based on the actual situation and the experiences of farmers to decide. Equal to the total amount of farmland water needs and irrigation of farmland deep product.
Water flows through the channel, the channel with the loss of water is also a wide range of factors. Select the general loss of pump water demand in the fields between 5% -25%. Pump operating time can be determined according to actual needs.
(2) The pump is selected to determine the head: the actual head to the field can be measured from the water surface to vertical channels Gao degree water or farmland surface. If the rivers and lakes, water surface should be dry when position Drought standard. Pump choice in determining the lift, but also consider the height of the pump installation. Gao degree = maximum pump installation pump allows suction height - water pump suction head loss loss of lift, generally small diameter (8 inches or less) pumps, suction tube when not too long, according to experience, absorbing losses bottomed valve Head of about two meters, without foot valve lift water loss nearly 1 meter.