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Section 1: INSTALLATION
1.1 Introduction
The tradename of this pump is GEM®, because of its suitability for the following laboratory applications:
Evaporators, such as the rotary type
Manifolds for vacuum
This pump also is well suited for use in gas analyzers, continuous gas-flow lasers, general-purpose drying, and
similar uses where a middle-range vacuum level is required. It is a good replacement for diaphragm (membrane)
and water aspirator pumps.
Its unique, patented technology permits pumping at any pressure range from O.1 mm Hg (100 microns) to
atmospheric. At these higher pressures, the pump uses the gas it is pumping to remove heat. Rotary-vane pumps
typically run hotter at these pressures, due to greater frictional forces.
This manual has been written for the care and maintenance of the Model 8890 Vacuum Pump. Take time to read
it carefully, and keep it for future reference. One of the most important aspects of any pump installation is the
precautions taken to prevent condensable vapors from collecting in the pump. Pay particular attention to Section
1-10 for ways to effectively pump condensable vapors.
1.2 Unpacking
Carefully remove the pump from the shipping carton. Keep all paperwork and inspection tags for future
reference. If shipping damage has occurred, a claim must be filed with the carrier immediately; keep the shipping
container for inspection by the carrier.
1.3 Pump Mounting
Rubber bumpers are supplied with the pump base. They isolate noise and eliminate creeping. For more rigid
mounting requirements the pump base can be the bumper holes to put the mounting bolts through. Refer to
Section 3 – Specifications for mounting hold location dimensions.
1.4 Pump Location
The pump should be located in a clean and well-ventilated area and adequate space should be provided wherever
possible for routine maintenance such as oil changes. For best performance, the pump should be located as
closely as possible to its system. Determining factors for pump locations should include length and size of
connections, the number of bends, and the type of exhaust connections.
1.5 Exhaust Provisions
Exhaust connections will be determined by the type of system to be exhausted and desired cleanliness of the air
surrounding the pump. Under normal pumping conditions nothing more than the optional exhaust filter will be
necessary. Refer to Section 9 – Accessories for various exhaust filters available. Where extreme exhaust
conditions are encountered, it is best to pipe the filter exhaust out of the building. The pump’s exhaust connection
is a threaded port, ¾-20, located opposite the inlet port on top of the oil reservoir. It will accept the Model 1417
Exhaust Filter, which is furnished with the pump, or can be used with the Model 1396J Hose Nipple, for 7/16 in.
ID hose.