Taylor-Wharton LP3 - Manual (Page 20)

3. Condensation may form on the container. Note that some icing or condensation is normal around
the piping connections of the vessel. Condensation may also occur on the vessel outer surface as
a result of high humidity.
4.
The relief valve will open continuously until the container is empty.
If a loss of vacuum integrity is suspected, the container’s normal evaporation rate (NER) should be checked.
The test procedure explained below measures the actual product lost over time.
1.
Fill the container with 200 pounds of liquid nitrogen.
2.
Close the liquid valve and the pressure building valve. Leave the vent valve open for the duration
of the test.
3.
Allow the container to stabilize for 24 hours after filling. Weigh the container. Record the
weight, date, and time.
4.
Move the container as little as possible during the test. After 48 hours, weigh the container a
second time. Record the weight, date, and time.
The following formula will provide the actual normal evaporation rate in pounds per day. An actual NER that
exceeds 25 pounds per day indicates a vacuum problem.
Daily NER = First Weight – Second Weight X 24
Time between weights in hours
If it has been determined that the vessel has a vacuum problem it will be necessary to repair or replace the
vessel. A skilled service technician should perform vessel replacement or repair. Contact Taylor-Wharton
customer service at 1-800-898-2657 for assistance in locating the closest service center.
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