Great Plains NH3 Safety - Manual (Page 33)

Great Plains Manufacturing, Inc. Table of Contents Index Anhydrous Application 29
2013-07-15 Table of Contents Index 407-551M
Stopping Application
Plan your stops. A safe stop requires depleting the
anhydrous, from the nurse tank withdrawal valve to the
tines or knives.
a. What is the wind direction?
b. Suspend application per “Suspending
Application”, below.
c. Put on your chemical gloves.
Be wearing your goggles.
d. Carefully approach the nurse tank from up-wind.
Expect some ammonia odor, but if it is extremely
strong, there may be an above-ground release in
progress due to malfunction or part failure. If so,
remain clear until the release subsides.
e. When safe to do so, shut off the nurse tank
withdrawal valve
(page 16).
f. Re-enter the tractor cab.
g. Turn MASTER switch ON.
h. Resume field application until reported rate begins to
fall. Increase rate to maximum (to fully open Control
Valve).
i. Continue field application until both cooler and
divider pressure gauges read zero.
j. Facing into the wind, raise the implement and stop.
k. Set the MASTER switch to OFF.
l. Wait at least 1 minute for row line vapor to dissipate.
m. Turn so that the wind is directly from the right.
n. Open all bleed valves. Standing up-wind of each,
and making sure orifices point away from you, slowly
open bleed valves at:
• nurse tank hose inlet end
(page 13)
• nurse tank hose outlet end (page 13)
• breakaway bleed valve or (page 42)
(whichever is safer)
• cooler temperature gauge (page 42).
o. Close all remaining operating valves:
• nurse tank hose inlet end
(page 13)
• nurse tank hose outlet end (page 13)
• emergency shut-off valve (page 42).
p. Wait at least one hour before moving implement to
any spot near unprotected people or livestock. It will
continue to out-gas ammonia vapor for some time.
Ball Valves: Trapped NH
3
Hazard:
Avoid routinely closing ball valves (other than the nurse tank
withdrawal valve) with liquid NH
3
in the lines. Fluid is
trapped in the line above the valve, may trigger relief valves,
and can get trapped inside the valve ball unless it has a bleed
port (not yet common on nurse tank hoses). See “Avoid Line
Traps” on page 37 and “Avoid Ball Traps” on page 38.
A typical ball valve can trap enough NH
3
to make a room the
size of a two-car garage uninhabitable (concentrations above
IDLH in moments). When the ball valve is later opened, while
warm, the NH
3
is expelled at high pressure. If the line is
pointed at your face, you could receive a fatal exposure.
A66
A61a
A61a
A13 A16
A27
A61a
A61a
A18