4 cylinder, 5 leak test, 6 checking chromatograms – Yokogawa GC8000 Process Gas Chromatograph User Manual
Page 355

<6. Maintenance>
6-2
IM 11B08A01-01E
Table 6.2
Inspection Items
Item
Recommended
Interval
Reading of pressure gauge on carrier gas cylinder
24 hours
Reading of carrier-gas pressure gauge
24 hours
Reading of sample-gas pressure gauge
24 hours
Reading of sample-gas fl owmeter
1 to 7 days
Reading of sample-gas bypass fl owmeter
1 to 7 days
Reading of purge-air pressure gauge
24 hours
Readings of pressure gauges on the hydrogen gas for combustion and nitrogen gas cylinders
1 to 7 days
Readings of pressure gauges for hydrogen gas for combustion and nitrogen gas
1 to 7 days
Reading of pressure gauge for combustion air
24 hours
Current temperatures of isothermal ovens, etc.
1 to 7 days
Calibration coeffi cient
1 to 7 days
LSV sample leak
7 days
Steam temperature adjustment at the sampling section
7 days
6.1.4 Cylinder
After replacing the cylinders for carrier gas, FID or FPD hydrogen gas for combustion, air, or
standard gas, always perform a leak test on the couplings around the regulators on the cylinder.
The leak test must be conducted two or three times every day, for the three days after replacing a
cylinder.
Ensure that the air is discharged from the system when replacing a cylinder. The installation of a
valve for discharging air is recommended.
6.1.5 Leak
Test
After replacing or repairing any of the parts for pipes located inside or outside the instrument,
always check the connections for possible leaks. This checkup procedure is called a leak test.
During a leak test, keep the pipes pressurized, apply soap water (Snoop or equivalent) to the
connections and check for possible leaks.
If a leak is found, retighten the connection or replace any defective parts and conduct leak test
again.
Wipe off soap water after the test.
Please note that any leak in the plumbing parts or connections may not only cause bad analysis
results or increase the gas consumption, but also could result in safety issues.
6.1.6 Checking
Chromatograms
After replacing any of the parts of the system, resume operation, record chromatograms several
times and compare the results with those shown in the Operation Data to ensure that the system
continues normal operations.
6.1.7
Recommended Parts List for Periodical Replacement
Table 6.3 is a list of parts that will require periodical replacement and their standard replacement
interval. The replacement interval differs depending on the process sample specifi cations
and the condition of use. Replace parts according to the adequate cycle to your GC8000. The
replacement interval is just a guide line. The actual replacement timing should be determined by
the customer’s experience in operating the system. The replacement interval does not mean that
the system is under warranty during the interval.
2nd Edition : May 11, 2012-00