7 Maintenance
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7.3.12 Replacing the gas cylinder (pressure regulator inspection)
Q
Precautions before replacing the cylinder
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Make sure there is sufficient ventilation before starting replacement.
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Firmly secure the gas cylinder so that it cannot fall over.
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Make sure that no paint, grease or oil gets on anything.
Never perform replacement work using oily gloves.
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Check the screw direction of the cylinder valve.
The valve of combustible gas cylinders turn left.
Q
Replacing the gas cylinder
When the residual pressure of the cylinder falls to 1 MPa or less, replace the cylinder.
1.
Close the cylinder valve.
2.
If it is possible to flow the gas remaining in the pipe and gauge to the analyzer's
main body, flow the gas to adjust the primary pressure of the pressure regulator to
0.
3.
For a pressure regulator with a needle valve, close the needle valve.
For the secondary pressure variable pressure regulator, turn the secondary
pressure adjusting handle counterclockwise as far as it will go.
4.
Replace the pressure regulator.
Note
Since the gas remaining in the pressure regulator is discharged when removing the cylinder, provide
adequate ventilation. When using poisonous gas, use protective gear such as a gas mask.
5.
Replace the old cylinder with a new cylinder.
Note
Take care so that the cylinder cannot fall over.
6.
Attach the pressure regulator.
When a packing is used at a sealing part of pressure regulator, replace the packing.
When a gasket with ring is used, replace the gasket with ring periodically.
Note
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In parts replacement, it is recommended that the gasket with ring to be replaced into the packing
without ring.
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The packing can be used only once. In replacing the cylinder, use the new packing.
The old packing, if continuously used, causes irregularity in sealing surface which easily attracts
metal powder to deteriorate the sealing performance.
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The typical replacing interval of gasket with ring is after 4 to 5 times of tightening.
In replacing it, remove a foreign material adhered to the packing or the gasket with ring if any.
CAUTION
Calibration gas is under high pressure. Handle it carefully.
• Check the installation state of the pressure regulator.
• Check the temperature of installation site.
(Storage and operating temperature is specified as 40ºC or less based on high-
pressure gas regulations.)
