Granville-Phillips Series 330, Instruction Manual, Page: 11 / 76

1 Safety Instructions
11
Series 330 Vacuum Gauge Controller
Instruction Manual - 330004 - Rev. 02
1.2 Equipment Grounding
1.3 Implosion / Explosion
Glass ionization gauges, if roughly handled, may implode under vacuum causing flying glass which
may injure personnel. If pressurized above atmospheric pressure, glass tubes may explode. A
substantial shield should be placed around vacuum glassware to prevent injury to personnel.
Danger of injury to personnel and damage to equipment exists on all vacuum systems that
incorporate gas sources or involve processes capable of pressurizing the system above the limits it
can safely withstand.
For example, danger of explosion in a vacuum system exists during backfilling from pressurized gas
cylinders because many vacuum devices such as ionization gauge tubes, glass windows, glass bell
jars, etc., are not designed to be pressurized.
Install suitable devices that will limit the pressure from external gas sources to the level that the
vacuum system can safely withstand. In addition, install suitable pressure relief valves or rupture
disks that will release pressure at a level considerably below that pressure which the system can
safely withstand.
Suppliers of pressure relief valves and pressure relief disks are listed in the Thomas Register under
“Valves, Relief” and “Discs, Rupture.”
Confirm that these safety devices are properly installed before installing the product. In addition,
check that:
a. The proper gas cylinders are installed,
b. Gas cylinder valve positions are correct on manual systems, and
c. The automation is correct on automated gas delivery systems.
d. Vacuum gauges with compression fittings may be forcefully ejected if the vacuum system is
pressurized.
Proper Grounding
All components of a vacuum system used with this or any similar high voltage
product must be maintained at earth ground for safe operation. The power cord of
this product shall be connected only to a properly grounded outlet. Be aware,
however, that grounding this product does not guarantee that other components of
the vacuum system are maintained at earth ground.
Complying with the usual warning to connect the power cable only to a properly
grounded outlet is necessary but not sufficient for safe operation of a vacuum system
with this or any similar high voltage producing product.
Verify that the vacuum port to which the Ionization Gauge or Convectron Gauge is
mounted is electrically grounded. It is essential for personnel safety as well as proper
operation that the envelope of the gauge be connected to a facility ground. Use a
ground lug on a flange bolt if necessary.
Install suitable devices that will limit the pressure to the level that the vacuum
system can safely withstand. In addition, install suitable pressure relief valves or
rupture disks that will release pressure at a level considerably below the pressure
that the system can safely withstand.