GREAT PLAINS Nutri-Pro NP30A, Operator'S Manual

Page: 27 / 172

NP30A or NP40A Table of Contents Index Metering Overview 23
2019-03-11 Table of Contents Index 407-502M
A16.Coupler Outlet Bleed Valve
This fitting is kept closed in normal operations.
When the breakaway is properly coupled, the inlet
bleed valve bleeds the entire assembly, and
applicator supply hose. On breakaway, this valve is
used to bleed the applicator side of the
disconnection. See “ Breakaway Event ” on
page 78.
A17.Supply Hose
This connects the breakaway coupler to the
emergency shut-off valve. Operator action is to
replace this hose, a time-dated part, when it
reaches the end of its operating life (see page 121).
A18.Emergency Shut-off Valve
The handle of this is valve has a rope which is
routed to the tractor cab (see page 32). Closing this
valve stops NH
3
flow to the cooler, metering system
and rows. There can still be a substantial amount of
NH
3
in the system, for some time, with this valve
closed. See the “ Using Anhydrous Ammonia
Safely ” manual (407-551M) for emergency
operation.
If the handle has a warning decal (page 13), the ball
may have a cavity that can contain a hazardous
amount of NH
3
if closed with the line full.
A19.Strainer
This filter contains a 20 mesh screen and two
ceramic magnets to remove debris from the NH
3
flow.
A20.Strainer Magnets
These capture ferrous metal debris of any size.
They need to be cleaned every 4 to 5 tank loads.
See page 124.
A21.AccuFlow™ Super Cooler (Heat Exchanger)
For effective application, NH
3
needs to remain in
the liquid state until released underground. This is
accomplished by refrigeration. Some of the flow is
tapped , fed back to the cooler at , vaporized
and used to chill the fluid passing from to .
A22.Cooler Intake
Liquid NH
3
enters the cooler here.
A23.Cooler Hydrostatic Relief Valve
In normal operation, this valve never activates. NH
3
can get trapped in the system between the
emergency shut-off valve and the On/Off
valve , if both valves are closed while the system
is charged. As the liquid warms and pressure rises,
this valve protects the system with periodic
releases.
This valve is set to activate at 350 psi, higher than
the nurse tank’s relief valve.
Operator action is periodic inspection, and to
replace this hydrostatic relief valve, a time-dated
part, when it reaches the end of its operating life
(see page 122). See “ Hydrostatic Relief Valve
Maintenance ” on page 119 for maintenance.
A24.Cooler Outlet
Chilled liquid NH
3
exits the cooler here.
A25.Flow Meter
This fitting converts fluid flow to pulses for the
SCS 450 controller. It has a range of 1-60 gpm. A
tag on the cable lead provides a “METER CAL”
number specific to the installed meter (and accurate
only for NH
3
fluid flow, and not NH
3
vapor flow).
A26.Drain Cap
The plumbing cross and lower cap below the
temperature gauge are provided to allow the gauge
probe to be exposed to the full NH
3
stream. This
cap does not require periodic clean-out.
A27.Temperature Gauge
This gauge reports the temperature of the chilled,
flowing, NH
3
. When NH
3
is not flowing, this gauge
slowly drifts up to ambient temperature.
Checking the temperature and pressure gauges
against the chart in the “ Using Anhydrous
Ammonia Safely ” manual (407-551M), or in the
Raven AccuFlow™ manual, indicates whether the
flowing NH
3
is in a liquid state.
Normal field temperatures of the chilled flowing NH
3
are in the range 20 to 83°F (-7 to 28°C).
Suffocation, Blinding and Burning Hazards:
See “ About Bleed Valves: ” on page 32.
A13
A32 A34
A22 A24
A18
A31
A28