13
05
Installation
Manual 1843 Rev B p/n 001843 0000
In all cases, the inlet manifolding should include
a 90° flanged elbow vertically oriented upward to
retain pump oil at low pressures, an isolation valve,
a flex connector, and a vent valve.
A flexible connection should be installed in
the suction manifold to provide freedom for
vibramounts. The vacuum piping must be well-
aligned with the pump connections so as not to
place a strain on the piping.
A vacuum isolation valve should be installed
adjacent to the suction port to be used for leak-
checking, shutting down the system or blanking-off
the pump. This will also allow the system to be
kept under vacuum while the pump is not running,
or to keep the pump operating while the system is
at atmospheric pressure.
Gauge connections should be provided on both
sides of the isolation valve. With this arrangement,
it is possible to check the system or the pump
for leaks or ultimate vacuum level performance
without disconnecting the vacuum piping.
Provisions for gauge installation and any other
drilling in the piping must be made prior to piping
installation; otherwise, drilling particles entering the
piping could be entrained into the pump.
Before connecting the suction manifolding,
distribute 4 quarts of oil over the three slide
pins by reaching through the suction port with a
container and pouring oil directly onto the slide
pins. Then rotate the pump by hand a minimum of
two revolutions to distribute the oil throughout the
pump interior.
During the initial operation and as long thereafter
as necessary, install a fine mesh screen across
the inlet connection to prevent abrasive or solid
particles left in the line from being sucked into the
pump. This screen can be removed when particles
no longer accumulate. If particles continue to
accumulate, install a filter in the line upstream of
the pump.
Proper Venting
The vacuum pump must be properly vented
to ensure all oil is removed from the pumping
chamber before the pump is turned off. Also, the
suction line must be properly vented to ensure oil
does not migrate into the process chamber.
Recommended vent valve sizes:
KT-150 = 0.75 inch
KT-300 = 1.0 inch
KT-500 = 1.5 inches
KT-850 = 2.0 inches
The vent valve must be open for at least 10
seconds before the pump is turned off to remove
all oil from the pumping chamber.
Discharge Manifolding
Discharge manifolding should be sized and
designed to prevent the following:
• Return of oil mist condensate to the pump
• Oil loss
• Oil mist in the discharged gas
Under normal conditions, the diameter of the
manifolding should not be less than the diameter
of the pump connection, and pipe length should
be kept to a minimum to avoid increased back
pressure.
The installation of an oil mist eliminator on the
discharge is recommended for all applications
(as shown in
Figure 5-3
). Oil that collects in the
eliminator should be returned to the pump. The
oil return kit will drain oil back into the separator
housing when the pump is operating at low
pressure or when the pump is stopped. If the pump
is to operate continuously, or normal operating
pressure is between 10 Torr (13 mbar) and 150 Torr
(200 mbar), the oil return should be connected to
the gas ballast as shown in
Figure 5-2
. If over
150 Torr (200 mbar), the oil return should be
connected to the pump inlet.
