Hoefer VP200 - Manual (Page 16)

If you will be evacuating a system containing
hazardous vapors:
• Adopt suitable measures to prevent the release of
dangerous, explosive, corrosive or polluting fluids
from the pump outlet. Always install the catchpots
at the outlet port and if required, install a suitable
treatment system. Observe applicable regulations
when disposing of chemicals.
• Take adequate precautions to protect yourself and
others from hazardous substances (e.g. wear protec-
tive clothing and work under adequate ventilation).
• Pumped gases or condensate may be released when
the gas ballast valve is open.
• Adopt suitable measures to prevent the formation of
explosive fluids or explosive or flammable mixtures,
e.g. control the air gas ballast, leaks, and compression.
• Avoid the formation of explosive mixtures in the
housing. If the diaphragm should crack, mechani-
cally generated sparks, hot surfaces or static elec-
tricity may ignite such mixtures. Use inert gas for
venting the diaphragm pump if necessary.
• When using an inert gas, avoid overpressure of more
than 0.2 bar.
• The pressure differential between the inlet and
outlet ports must not exceed 1 bar. Attempting to
start the motor at higher pressure differentials may
result in blockage or damage to the motor.
• If a valve is installed to isolate the exhaust end of
the system, make sure that the pump cannot be
operated with the valve closed. A closed valve will
cause the system to pressurize and possibly burst.
• The pump will not reach maximum vacuum until it
has run approximately 15 minutes to warm up. If
maximum pressure is required immediately upon
connecting the pump to the system, install a suit-
able in-line valve upstream from the inlet port. A
valve placed here is also useful for isolating the
pump to clear it before shutting it off.
• Pumping at high inlet pressure may lead to over-
pressure at the gas ballast valve due to the high
compression ratio of the pump.
• Construct the system so that pump failure (e.g.
during a power failure) will not create a hazardous
situation.
•
p8
Note: The pump’s residual
leak rate is extremely low, but
an exchange of gas between
the environment and the
vacuum system may occur.