Ulvac CRYO-U Series Instruction Manual page 74

Maintenance
◇The gas charge inlet of the compressor unit is 1/4B male flare.
◇Use helium gas with purity of 99.999% or more.
Charge helium gas as follows:
１．When mounting the regulator on a new helium bottle, perform the following procedures in
order to remove air and fill helium gas in the gas line between the regulator and the bottle
valve first.
ａ．Turn the regulator handle clockwise to open the regulator a little.
ｂ．Slowly open the bottle valve, and purge the regulator and gas line for several seconds.
ｃ．Turn the regulator handle counter-clockwise to close the regulator.
Do not open the bottle valve immediately after attaching a regulator, as it diffuses the air
between the regulator and bottle valve into the helium bottle, and contaminates helium gas.
Never bring your face in front of the pressure gauge when opening the bottle valve or turning
the regulator handle.
２．Remove the front panel of the compressor unit.
３．Connect the helium charging hose as follows:
ａ．Connect the charging hose to the regulator.
ｂ．Loosely connect the charging hose to the charge inlet on the compressor unit so that
helium gas can be slightly blown out here.
ｃ．Open the regulator until the outlet pressure reaches 0.1 to 0.2 MPaG. Allow helium gas to
flow out from the charging hose for about half a minute. Meanwhile, open the charge
valve slightly in order to drive out the air that exists between the charge valve and the
charge inlet.
ｄ．Tighten the flair nut at the end of charging hose and close the charge valve. Helium gas
charge in the line between the regulator and the charge valve on the compressor has
been completed.
４．Adjust the outlet pressure of the regulator at 1.8 MPaG. Pressure relief valve has to be
mounted as well as the regulator. The set pressure of the pressure relief valve is 2.4MPaG.
8-6
CAUTION
WARNIN
ULVAC CRYOGENICS INCORPORATED
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