Chapter: INSTALLA
nON
Topic: InstallingGasSupply
FlowSnubber Flit
-;;;;;)--="j.~~ ;;C:~
(Flammable Gases Only)
Exit Pressure
(DO
more
than 20
psi
greater than
required GC prusurt with
• maximumof
80
psi)
SbutoffVall"e
---'I
ToGC
PressureRegulator
~-':~~
---':Total Remaining
C}"linder Pressure
-j'-- -
valve Stem
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Commercial
Gas Cylinder
Once the necessary gas supply cylinders have been properly secured to a strong foundation
(see previous page). related plumbing must
be
carefully installed and routed. Always use a pressure
regulator on the cylinder to provide proper pressure regulation to the GC. A shutoffvalve should be
inserted
on the output side of the regulator to permit line service when needed. A flow snubber on the
output side of the regulator is also
highly
recommended for hydrogen and
all
other flammable gases.
Unless youareutilizing anECD, refrigerationgrade 118" copper tubing is reconunended for
all
of the
gas lines from the cylinder pressure regulator to the GC. Due to the exceptionally high sensitivity of
anECD, GCs equippedwith this detector require 1116" stainless steel tubing to reduce the potential
for gas line contamination. It is also advisable to flame the stainless steel tubing with a torch until it
changes colorwhile flushingwith clean carrier gas. This
will
help to remove anypotential preexisting
contaminants fromwithin the tubing.
An
oxygen filter is also a worthwhile option for
ECn
carrier
gas supplylines due to thedamaging effects of oxygen on thedetector. Plastic tubing should never
be
used for the gas supply lines due to its permeability to contaminants such as oxygen which can cause
damage to thermal conductivity detectors (TCDs) and capillary
COIUOUlS
as well as ECDs. Proper
supply line routing is also very important. Avoid routing gas supply lines near electrical outlets to
eliminate any potential hazards associated with electrical shorts and/or flammable gases. Metal gas
lines canvery easily fall across the two prongs of any plugged in electrical device and start a fire
if
routednear anelectrical outlet. After gas supplylineshavebeenproperlyinstalled, pressurizethe lines
and check
all
associated finings for potential leaks. In order for electronic pressure control units to
operate properly, do not set gas pressure coming from the cylinders anymore than 20 psi greater than
GC requirements. For example, if carrier gas head pressure is set to 10psi at the GC, then set carrier
supply pressure from the cylinder above 10 psi but no greater than 30 psi.
C:\MANUALiCHAPTERIIISSTOA.S2.IX>OTM
REV. 08-<17.96
