Taylor-Wharton Liquid Withdrawal Device - Manual

LIQUID
WITHDRAWAL DEVICE
For Liquid Nitrogen
LD25, LD35, and
50LD Dewars
TW-43
The Liquid Withdrawal Device (LWD) provides convenient
pressure transfer to liquid nitrogen from LD25,LD35, and
50LD Dewars. The device clamps directly to the special
neck flange that is found under the plastic trim collar
around the neck of these containers.
Flow rates up to 8 liters per minutes are possible at
operating pressures up to 10 psig (0.7 bar/69 kPa). Liquid
can be dispensed directly from the LWD via the spout
provided, or through a standard cryogenic hose connected
to the liquid outlet.
Filling a Dewar is accomplished by pressure transfer
through the withdrawal device. (See Filling Instruc-
tions.) This filling method allows replenishment of the
liquid supply in the Dewar without removing the LWD,
while keeping the liquid saturated at a pressure sufficient
to sustain liquid withdrawal.
Before using this equipment, read these instructions
carefully. Also, read and understand the instructions sup-
plied with your Dewar and the Handle with Care booklet
packed with all Liquid Nitrogen Dewars. The Handle with
Care booklet (Form TW-10) gives detailed information on
the safe handling of liquid nitrogen. Additional copies of
these publications can be obtained from your supplier. Do
not modify LWD or Dewar or use in a manner other than that
described in accompanying instructions and documentation.
Contact with liquid nitrogen or cold gas may cause
serious freezing (frostbite) injury. Do not touch liquid or
cold metal surfaces with your bare skin. Always wear a face
shield and gloves when transferring liquid nitrogen.
Nitrogen gas can cause suffocation without warning.
In a confined area, nitrogen gas from this equipment may
displace air required for breathing. Store and use this
equipment only in well-ventilated areas.
Use only containers designed for low-temperature
liquids. Cryogenic containers should be filled SLOWLY to
minimize stresses which can damage the container.
Vent all pressure from a Dewar before attempting to
remove the Liquid Withdrawal Device. If the band clamp
securing the LWD to a dewar is loosened while there is
pressure in the Dewar, cold gas or liquid could be expelled
causing personal injury.
Liquid Withdrawal Device is for use with liquid nitrogen
only. LWD is for use on specific model Taylor-Wharton
Dewars listed above.
Pressure in Dewar with LWD installed should never
exceed 10 psi. Fill dewar from supply source at 22 psi or
less. Do not pressurize using compressed air.
Safety