GREAT PLAINS NP2540, Operator'S Manual, Page: 102 / 196

2019-04-12 Table of Contents Index 417-459M
NP2540 Table of Contents Index Fertilizer Rates 98
Install Orifice Plates
Refer to Figure 68
Insert the plate inside the gasket supplied with the
nozzle Insert the gasketed plate with the legend side
facing out the nozzle outlet (typically up).
In general, the orifice needs to be small enough to
create enough pressure in the manifold to operate the
check valves in the boom clamps, but not so much that
the system dumps product at the boom relief valve.
The recommend operating pressure is: 15 to 40 psi
Using an orifice size too large can result in unequal flow
at rows, intermittent flow, and flow stoppage at rows
where pressure falls below the 8 psi required to open the
clamp check valve. Using a size too small can cause
excess back-pressure resulting in material dumping at
the boom relief valve.
Use the same size at all active rows.
Excess Back-Pressure Risk:
If using a size of 0.048in or larger, remove the 828-046C
nozzle from the outlet of the coulter tine.
Tramlines and Doubled Rows
If your operations result in row units running in the same
row (or rows) in opposing passes, take steps to avoid
double application (run those rows at half rate).
•
For doubled rows using standard nozzles, use orifice
plates having
1
/
2
(or slightly more than
1
/
2
) the
Port Area of the other rows. See the table at right,
right-most column, for the Port Area of each plate
call size.
•
For doubled rows using VeriFlow nozzles, install
829-144C half-rate nozzles on those rows.
For either nozzle type, an adjustment to the rate
calculation is required to compensate for the half-rate
rows. Reduce the applicator swath by
1
/
2
row space for
each row set to half rate.
L39
L37
 Replacement nozzles include gaskets.
Gaskets may also be ordered separately as
Great Plains part number CP18999-EPR.
Agricultural Chemical Hazard:
Wear protective gloves when changing orifice plates and
strainer screens. Consult material manufacturer or supplier
documents for proper handling and steps to take if skin contact
occurs.
Alternate Orifice Plates
Figure 68
Fertilizer Orifice Plate
29984
L37
Orifice Part Port Port
Size Number Diameter Area
20 832-052C 0.020 in 0.20 mm²
28* 832-056C 0.028 in 0.40 mm²
34* 832-053C 0.034 in 0.59 mm²
48* 832-054C 0.048 in 1.17 mm²
59 832-057C 0.059 in 1.76 mm²
80 832-055C 0.080 in 3.24 mm²
98 832-059C 0.098 in 4.87 mm²
29993 * Sizes standard in many fertilizer bundles.
Check your accessories before ordering.
2
3
1
1 2
3
1