Gas ballasting the roughing pump 4-23
• A screwdriver-operated gas ballast valve. See page 4-23.
• A handle-operated gas ballast valve. See page 4-24.
Gas ballasting a pump with a screwdriver-operated gas ballast
valve
Required material
Flat-blade screwdriver
To gas ballast the roughing pump:
1. Use the flat-blade screwdriver to turn the gas ballast valve on the pump
a quarter-turn to the open, , position.
Warning: To avoid burn injuries, take great care while working with the
roughing pump; it can be hot.
Caution: To avoid damage, follow these guidelines:
• Do not vent the instrument when the roughing pump is gas
ballasting.
• Do not gas ballast the roughing pump while the instrument is in
Operate mode.
• Avoid gas ballasting the roughing pump for more than 2 hours.
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