[labnetwork] Cryo-piping contractors for LN2 piping sought

[Dennis Schweiger]

Meredith,

We have five phase separators in our facility, all supplied by Vacuum
Barrier Corporation, and whenever we see the icing issue, it's
usually attributed to moisture in the vacuum jacket, and we typically will
warm the system up, and purge with dry Nitrogen for 24 hours.  that
corrects the issue, and then we refill the system with cryogenic material
after we've pumped the vacuum jacket down.  Also, all of our
phase separators have a heater on the "vent" port of the phase separator to
keep it from icing up at that discharge location.  These guys aren't that
far from you.

*VACUUM BARRIER CORPORATION*

4 Barten Lane

Woburn, MA 01801 USA

781.933.3570

www.vacuumbarrier.com

Have you tried doing a Helium leak test on your vacuum jacket to make sure
you don't have a leak?

Are you sure that your high vacuum pump is operating correctly?  We've had
issues with the heater in the diffusion pump failing, and we weren't
getting a low enough vacuum.

Facilities Supervisor
University of Michigan/LNF

Dennis

734.647.2055 Ofc


On Tue, Feb 28, 2023 at 3:53 PM Metzler, Meredith G. (Fed) <
meredith.metzler at nist.gov> wrote:

> We are hoping the community can assist us in identifying a vendor who can
> inspect an existing LN2 delivery piping system in the cleanroom for our
> cryo-etch tools. We've recently started experiencing issues with a phase
> separator that keeps building up a large block of ice on the outside of it.
>
>
>
> We have a 5 Gallon phase separator made by Chart Inc. with one outlet. It
> feeds liquid nitrogen to several tools in the etch bay of the cleanroom.
> The LN2 system is house regulated to 40 PSI at the inlet. The unit
> separates the gaseous N2 from the liquid. The liquid is stored in the 5
> gallon volume surrounded by a vacuum jacket to prevent icing. The final LN2
> inlet connection to the phase separator, the exhaust connection, and the
> over pressure relief connection seem to be the biggest points of failure.
> At these three points we have cold air and moisture condensation that forms
> an ice ball.
>
>
>
> Although, we have made many at wrapping and insulating these connection
> points, we cannot quite get the coverage to eliminate this ice ball.
>
>
>
> Does the community have any preferred cryo-piping contractors they can
> recommend to assist with solving this issue and any of our future
> cryo-piping needs?
>
>
>
> Thanks!
>
>
>
> Meredith Metzler
>
> National Institute of Standards and Technology, Physical Measurement
> Laboratory
>
> Process Engineer – Center for Nanoscale Science and Technology Facility,
> NanoFab
>
> 100 Bureau Drive, Mail Stop 6201, Building 216
>
> Gaithersburg, MD 20899
>
> 301-975-8187
>
> meredith.metzler at nist.gov
>
> https://www.nist.gov/cnst
>
>
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