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OPERATING
INSTRUCTIONS FOR CLPB SERIES
SELF- PRESSURIZING DEWARS
Introduction
The container
consists of an inner stainless steel cylinder securely supported
in an outer jacket shell. The space between the inner and
outer vessels contains a highly efficient insulation material
and is evacuated.
Safety
Devices
A relief
valve and a rupture disc protect the inner liquid reservoir,
both located on the manifold.
A combination
evacuation valve and relief device is provided to service
the vacuum space. This protects the container in the event
of a leak in the inner reservoir. If this device vents, contact
Cryofab; do not attempt to use the container or re-evacuate
the insulation space.
Gauges
A pressure
gauge is provided indicating inner vessel pressure. A liquid
level gauge is provided to indicate approximate container
contents (CL series only).
Pressure-Building
System
This
container is equipped with an integral pressure-building system
to aid in liquid withdrawal. The pressure-building system
consists of the pressure-building coil, the pressure-building
valve, and the pressure-building regulator all connected in
series.
The pressure-building
regulator maintains a preset vessel pressure during liquid
withdrawal as long as a sufficient liquid supply is in the
container and the pressure-building valve is open. If a different
pressure setting is required, the pressure-building regulator
can be adjusted. To lower the setting, turn the adjusting
screw counterclockwise To increase the setting, turn clockwise.
NOTE
When the
pressure-building system is operating, frost will appear near
the bottom of the container.
Handling
These
containers are designed for use in the upright position and
should not be laid on their side. If a container must be lifted,
use a forklift or similar device beneath the base, or hoist
by means of the lifting slots in the halo ring struts. Do
not attempt to lift by the handles or by means of slings around
the shell.
Filling
These
containers can be filled from a pressurized liquid source
using the following procedure. Connect the liquid source to
the fill/withdrawal valve (labeled liquid) using a suitable
transfer line. Open the vent valve (labeled vent) and the
fill/withdrawal valve. To begin the transfer, open the liquid
source valve. Keep the container pressure below the relief
valve setting during filling. Throttle the flow from the liquid
source if necessary.
WARNING
A cold
stream of gas and or liquid will exit from the vent valve.
Keep clear of exiting stream.
When the
container is filled to maximum capacity, liquid will start
to exit from the vent valve. At that point shut off the liquid
source valve. Disconnect the transfer line and shut the fill/withdrawal
and vent valves.
Withdrawal
Transferring
liquid from the container is accomplished by the following
procedure. Be sure the vent valve is closed and check the
pressure gauge to see that the vessel pressure is adequate
for the intended application. If additional pressurization
is required, open the pressure building valve to operate the
integral pressure building coil. With the pressure building
system functioning, the preset pressure will be maintained
throughout the withdrawal, as long as a sufficient liquid
supply is present.
Attach
a suitable transfer line to the fill/withdrawal valve. Open
the fill/withdrawal valve as far as necessary to obtain the
desired flow rate. When the transfer is complete, close the
fill/withdrawal valve and disconnect the transfer line. The
pressure-building valve may be left open, if desired. This
may, to a limited extent, determine the operating pressure
of the vessel until the liquid is saturated.
Changing
Service
Although
these containers can be supplied the factory for LN2,
LARG, or LOX service, do not attempt to change the service
for which the container was originally supplied without consulting
the factory.
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