Varian VHS-4, Instruction Manual

Page: 19 / 60

VHS-4, VHS-6 and VHS-250 Diffusion Pumps
xix
Dangerous Substances
Chemical Dangers of Acetone and Alcohol
Diffusion pumps are typically cleaned with acetone or alcohol. Acetone, alcohol, and most
other solvents are irritants, narcotics, and depressants, and/or carcinogenic. Their inhalation
and ingestion may produce serious effects. Even absorption through the skin can result in
moderate toxicity.
Ensure that cleaning operations are always performed in large, well-ventilated rooms. The
use of a self-contained breathing apparatus may be necessary depending upon the solvent
type and vapor concentration in surrounding air.
Poisonous and Corrosive Compounds
When pumping poisonous, reactive, and/or corrosive gas, vapors, or chemicals, proper
operation and regeneration do not always ensure that all hazardous materials have been
totally removed.
If hazardous gas, vapors, chemicals, or combustible mixtures are pumped, sufficient
quantities may exist during operation or remain after regeneration to cause severe injury or
death.
Pump Fluids
Overheating the pump fluid, exposing it to air or reactive materials, or overpressurizing it
above the normal operating range (approximately 1 x 10
−
3
Torr / 1.3 x 10
−
3
mbar)
decomposes the fluid and possibly makes it toxic. This is especially true of backstreamed
mechanical pump oils which are more volatile (unstable). Overheating of accidentally
introduced or backstreamed mechanical pump oils cannot be protected against by thermal
switches which are set for diffusion pump oil.
Process Gasses
These gasses are frequently toxic, flammable, corrosive, explosive, or otherwise reactive.
Vacuum Technologies has no control over the types of gasses passing through your diffusion
pump as these are entirely under the control of the process user and/or the hardware
systems integrator. Since these gasses can cause serious injury or death, it is very important
to plumb the exhaust of the pump to the facility’s hazardous gas exhaust system which
incorporates appropriate filters, scrubbers and similar components to ensure that the
exhaust meets all air and water pollution control regulations.