VICI D-2-I - Manual (Page 19)

15
Installing and Purging the Gas Regulator
1. Make sure the on/off valve on the helium cylinder is completely closed.
Screw the CGA fitting nut of the regulator into the helium cylinder. Go
beyond finger-tight, but do not tighten the nut all the way – some leakage
is required for the purging operation.
2. Turn the output pressure regulating knob completely counterclockwise.
3. Open the cylinder on/off valve slightly and quickly close it again.
4. Adjust the tightness of the regulator connecting nut to allow a pressure
reduction of ~690 kPa/sec (100 psi/sec). With a new bottle, the gauge
should start out at about 14 MPa (2000 psi).
5. When the pressure drops into the 1.4 - 3.4 MPa (200 - 500 psi) range,
open the cylinder on/off valve slightly and quickly close it again.
6. Repeat Step 5 eight or ten times to be certain that all the air is purged.
On the final purge, tighten the regulator connecting nut very securely as
the pressure approaches the 2.1 - 3.4 MPa (300 - 500 psi) range.
7. Open the cylinder valve to pressurize the regulator once again. Close
the valve and observe the needle of the high pressure gauge for 15 minutes.
If it doesn’t move, there is no critical leak on the high pressure side of the
regulator.
CAUTION: Never use leak detecting fluids on any part of
this system.
Installation
GAS CHROMATOGRAPH
COLUMN INJECTOR
TEE
(ZT1)
HELIUM
PURIFIER
DISCHARGE GAS
(99.999% He)
TGA-R-50F50P
RESTRICTOR
(50 mL/min minimum)
VENT
COLUMN INLET
DISCHARGE GAS
INLET
Figure 4: Gas connections for a PD-D2-IS system