STEP 1 - DETERMINE FLOW RATE
Most growers start by selecting the flow rate for their spray stake. See the Product Selection Guide chart for some general recommendations. Remember, these are not strict limitations, just general guidelines. Many growers with larger pots use higher flow spray stakes, while others prefer to use lower flow spray stakes and simply operate them longer. The next consideration is how long a row or “run” of pots you want to water. Lower flow spray stakes can water longer runs than higher flow spray stakes. The Pipe Sizing and Maximum Row Length chart will help ensure your spray stake selection fits your design - this will be covered in a later step.
STEP 2 - DETERMINE SPRAY STAKE SPACING
After selecting the flow rate for the spray stakes in Step 1, the spray stake spacing needs to be determined. Normally this is the spacing between the pots. If your pots are spaced at 48” and you are using one spray stake per pot, your spray stake spacing is 48”. If you are using more than one spray stake per pot, then the spray stake spacing is the average spacing between spray stakes. For example, if you had pots spaced 48” apart and are using two spray stakes per pot, the average distance between spray stakes is 48” ÷ 2 = 24”.
STEP 3 - DETERMINE SUPPLY PIPE SIZING
The Pipe Sizing and Maximum Row Length chart will help you select the pipe sizing appropriate for your design. Larger pipes allow for longer runs and this chart will help you pick the right size pipe. The chart lists both the maximum run length in feet and the number of pots (shown in parenthesis). Using the Spray Stake color (flow rate) you selected in Step 1 and the spacing you determined in Step 2, read across the Pipe Sizing and Maximum Row Length chart until you find the length which is greater than your row length. Refer to the column heading above this number for the pipe size to use.
Note: This chart is intended for designs on flat ground. For sloping ground, use a qualified Netafim dealer to assist you with your design.
STEP 4 - ZONE SIZING BASED ON AVAILABLE FLOW RATE
Multiply the number of spray stakes you have in each row by the number of rows you will be watering at the same time. This is the total number of spray stakes you want to operate at the same time - a watering “zone”. The Zone Flow chart will convert that number of spray stakes into gallons per minute (GPM). This zone flow will be helpful in determining the sizing for mainline pipes and other system components.
STEP 5 - SIZING THE SYSTEM COMPONENTS
Recommendations for sizing basic versions of valves, filters, water meters and pressure regulators for your zone flow can be found in these charts. Detailed additional information for performance and specifications can be found on the technical sheets for each component. These are available on our website at www.netafimusa.com, by calling Customer Service at 888-NETAFIM or through our network of qualified dealers.
Note: Sizing the mainline pipes should be done through a certified irrigation designer.