Great Plains NP4000B Operator Manual - Manual (Page 31)

Great Plains Manufacturing, Inc. Table of Contents Index Application Overview 27
2014-05-14 Table of Contents Index 417-199M
A61.Bleed Valve(s)
Hose valves typically have bleed valves. Have the
hose provider explain exactly what is bled by each
bleed valve.
The purpose of a bleed valve is to perform a
controlled release, via an orifice, of any fluid or gas
trapped in the closed line prior to disconnect at a
nearby Acme fitting.
A single bleed valve may be located on the inlet or
outlet side of the valve, and only protects that side
of the circuit when the valve is closed. More rarely, a
shut-off valve has bleed valves on both sides of the
valve. An older ball valve may have a bleed valve for
the ball itself.
A65.Withdrawal Valve
In field operations, this valve is
opened first, and
closed first.
The withdrawal valve is the application outlet valve.
It is usually located on the tank top, but may be
located on the bottom. It is color coded red or
orange.
A67.Pressure Gauge
This gauge reports the pressure (usually in psi) of
the NH
3
gas at the top of the tank. The reading
varies with tank and ammonia temperature.
Suffocation, Blinding and Burning Hazards:
See “About Bleed Valves:” on page 38.
Ammonia Release Hazard:
Never open the withdrawal valve unless:
a. all other valves and bleed valves, are closed, or;
b. the applicator is configured and ready for use.
Always be on the up-wind side for valve operation.
Always open slowly.
Always check for signs of release when opening this
valve.