STEP 1
DETERMINE THE DRIPPER SUPPLY PIPE SIZING
Using the top row of the WPCJ Dripper Supply Pipe Sizing Chart, select the dripper spacing to be used. By matching this to the length of the pipe column, the correct size Dripper Supply Pipe can be determined.
STEP 2
DETERMINE HOW MANY BASKETS CAN BE WATERED AT THE SAME TIME
Use the Zone Flow chart to help calculate how much water it takes to operate one zone of baskets. Select from the chart the number of baskets to be watered at the same time. Use the flow that results from this to determine the correct sizing for the pipe and control head components. Each dripper has a flow rate of 0.5 gallons per hours (GPH).
STEP 3
SELECT THE DISTRIBUTOR AND MAINLINE PIPE SIZES
Using the maximum flow demand from the largest zone or combination of zones which may be watered at the same time, you can size the Distributor and Mainline pipes from the Distributor and Mainline Pipe Sizing chart. Either PVC or polyethylene pipe can be used for the Distributor and Mainline. If PVC is used above ground, it should be painted to prevent light penetration, which can result in growth of algae within the pipe. This chart is appropriate for distributor lengths up to 40 feet and mainlines up to 100 feet. When slopes are a factor, when longer length pipes are needed, or for other special conditions, please consult a certified Netafim System Designer for assistance.
STEP 4
SELECT THE MAJOR SYSTEM COMPONENTS
Size the Control head (valve, filter and pressure regulator) based on Flow Demand determined in Step 2. It is very important to recognize the minimum flow for the pressure regulator. Make sure to size the pressure regulator by determining both the minimum and maximum number of baskets which may be watered at the same time. Use a 35 psi Low Flow Pressure Regulator with zones of 400 baskets or less. The size of the Control Head components should be determined by the flow demand and not the size of the pipe that connects to them. Mixed pipe sizes and components (e.g.1” filter on 1 ½” pipe) will have no negative effect on the operation of the system if properly sized by the flow demand.
