Great Plains NP3000A Operator Manual - Manual (Page 114)

110 NP3000 and NP3000A Table of Contents Index Great Plains Manufacturing, Inc.
407-613M Table of Contents Index 2014-04-22
Clearing Plugged Tines
Tines can get plugged at release ports , due to sticky
soil, reverse movement and other causes. Routinely
check tines for evidence of plugging just prior to nurse
tank hitching. More rarely, unusual field debris can cause
a tubing disconnect at a tine. Treat it as a plugged line
until you confirm otherwise.
Elevated Ammonia Exposure Hazard:
Follow clearing instructions carefully. Wear your PPE
a .
Plugged delivery lines with tubing still attached can hold
significantly greater than normal NH
3
liquid which is not likely
to be mitigated by the normal Discharge procedures. Hastily
disconnecting a charged line will release a dangerous amount
of NH
3
liquid and vapor. Your PPE is not designed to protect
you against such a release. Burning, respiratory injury,
blinding or death could result.
Refer to Figure 69
Clearing Plugged Application Tubes
A plugged application tube often results in the delivery
tubing lifting off the tine tubing at the clamp
(an “open line plug”). The disconnect is usually easy to
spot in the field as a condensation cloud from the row.
The row is likely to be taking more than its equal share of
NH
3
from the flow divider. You may see a drop in
pressure at the flow divider gauge ( on page 29).
If the plugged line remains closed (“closed line plug”),
the tubing may be completely full of liquid NH
3
by the
time you detect the problem. You may notice an increase
in pressure at the flow divider gauge
, or pressure
pulses, as trapped liquid warms, periodically vaporizes,
and blows back into the flow divider (
on page 29).
Clearing Open Line Application Plugs
1.
Stop operation (page 64).
2. Discharge the system (page 108).
3. If the tine tubing is cold, wait for it to warm to ambient
temperature (and vaporize any liquid NH
3
inside).
4. Use a thin flexible tool (a coat hanger wire may
suffice) to clear the tine tube from above or below.
5. Reconnect the application tubing. Squeeze the
spring clamp
. Slide it up the delivery tubing. Push
the delivery tubing onto the tine tube about
3 ⁄
4
inch (19 mm). Slide the spring clamp to centered
in the overlap.
Clearing Closed Line Application Plugs
1.
Review the WARNING at the top of this page.
2. Stop operation (page 64).
3. Discharge the system (page 108). The standard
discharge is not likely to adequately discharge any
plugged or closed lines. Expect continuing vapor
release at non-plugged rows. The plugged line
discharges back through the flow divider, and out the
other rows.
4. Wait until the plugged tine has warmed to ambient
temperature, and the liquid level in the plugged loop
is about the same as in the open loops.
5. Squeeze the spring clamp . Slide it up the tubing.
Pull the delivery tubing off the tine tubing.
6. Use a thin flexible tool (a coat hanger may suffice) to
clear the tine tube from above or below.
7. Reconnect the application tubing. Squeeze the
spring clamp. Slide it up the delivery tubing. Push the
delivery tubing onto the tine tube about
3 ⁄
4
inch (19 mm). Slide the spring clamp to centered
in the overlap.
a. PPE: Personal Protective Equipment
1
2
A45
Figure 69
Dual Tine Delivery/Vapor Tubes
34990
1
1
A45
A42
A42
A40
2
2