RWF ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-600 IOM (OCT04)
Page 4
Installation
FOUNDATION
Each
RWF
Rotary Screw Compressor Unit is shipped
mounted on a wood skid which
must
be removed prior to
unit installation.
Allow space for servicing the unit
per factory drawings.
The first requirement of the compressor foundation is that it
must be able to support the weight of the compressor pack-
age including coolers, oil, and refrigerant charge. Screw
compressors are capable of converting large quantities of
shaft power into gas compression in a relatively small space
and a mass is required to effectively dampen these relatively
high frequency vibrations.
Firmly anchoring the compressor package to a suitable
foundation by proper application of grout and elimination of
piping stress imposed on the compressor is the best insur-
ance for a trouble-free installation. Use only the certified
general arrangement drawings from Frick to determine the
mounting foot locations and to allow for recommended clear-
ances around the unit for ease of operation and servicing.
Foundations must be in compliance with local building codes
and materials should be of industrial quality.
The floor should be a minimum of 6 inches of reinforced
concrete and housekeeping pads are recommended. Anchor
bolts are required to firmly tie the unit to the floor. Once the
unit is rigged into place (See RIGGING and HANDLING),
the feet must then be shimmed in order to level the unit. The
shims should be placed to position the feet roughly one inch
above the housekeeping pad to allow room for grouting. An
expansion-type epoxy grout must be worked under all areas
of the base with no voids and be allowed to settle with a slight
outward slope so oil and water can run off of the base.
When installing on a steel base, the following guidelines should
be implemented to properly design the system base:
1.
Use I-beams in the skid where the screw compressor will
be attached to the system base. They should run parallel to
the package feet and support the feet for their full length.
2.
The compressor unit feet should be continuously welded to
the system base at all points of contact.
3.
The compressor unit should not be mounted on vibration
isolators in order to hold down package vibration levels.
4.
The customer’s foundation for the system base should fully
support the system base under all areas, but most certainly
under the I-beams that support the compressor package.
When installing on the upper floors of buildings, extra precau-
tions should be taken to prevent normal package vibration
from being transferred to the building structure. It may be
necessary to use rubber or spring isolators, or a combination
of both, to prevent the transmission of compressor vibration
directly to the structure. However, this may increase package
vibration levels because the compressor is not in contact with
any damping mass. The mounting and support of suction
and discharge lines is also very important. Rubber or spring
pipe supports may be required to avoid exciting the build-
ing structure at any pipe supports close to the compressor
package. It is best to employ a vibration expert in the design
of a proper mounting arrangement.
In any screw compressor installation, suction and discharge lines
should be supported in pipe hangers (preferably within 2 ft. of
vertical pipe run) so that the lines won’t move if disconnected
from the compressor. See table for Allowable Flange Loads.
ALLOWABLE FLANGE LOADS
NOZ.
MOMENTS (ft-lbf)
LOAD (lbf)
SIZE
AXIAL VERT. LAT. AXIAL VERT. LAT.
NPS
M
R
M
C
M
L
P
V
C
V
L
1
25
25
25
50
50
50
1.25
25
25
25
50
50
50
1.5
50
40
40
100
75
75
2
100
70
70
150
125
125
3
250
175
175
225
250
250
4
400
200
200
300
400
400
5
425
400
400
400
450
450
6
1,000
750
750
650
650
650
8
1,500 1,000 1,000 1,500
900
900
10
1,500 1,200 1,200 1,500 1,200 1,200
Frick
®
recommends consulting a licensed architect to de-
termine the proper foundation requirements for any large
engine or turbine drive.
When applying screw compressors at high pressures, the
customer must be prepared for package vibration and noise
higher than the values predicted for normal refrigeration duty.
Proper foundations and proper installation methods are vital;
and even then, sound attenuation or noise curtains may be
required to reduce noise to desired levels.
For more detailed information on Screw Compressor Foun-
dations, please request Frick
®
publication S70-210 IB.
RIGGING and HANDLING
This screw compressor package
may be top-heavy. Use caution in
rigging and handling.
The unit can be moved with rigging, using a crane or forklift,
by hooking into the four lifting eyes on the oil separator. If a
motor is mounted, ap propriate adjustment in the lifting point
should be made to compensate for motor weight. Adjustment
of the lifting point must also be made for any additions to
the standard package such as an external oil cooler, etc.,
because the center of balance will be effected.
The unit can be moved with a forklift by forking under the skid,
or it can be skidded into place with pinch bars by pushing
against the skid.
NEVER MOVE THE UNIT BY PUSHING
OR FORKING AGAINST THE SEPARAT OR SHELL OR ITS
MOUNTING SUPPORTS.
SKID REMOVAL
If the unit is rigged into place, the skid can be removed
by taking off the nuts and bolts that are fastening the unit
mounting supports to the skid before lowering the unit onto
the mounting surface.
If the unit is skidded into place, remove the cross mem bers
from the skid and remove the nuts anchoring the unit to the
skid. Using a 10-ton jack under the separator raise the unit
at the compressor end until it clears the two mounting bolts.
Spread the skid to clear the unit mounting support, then lower
the unit to the surface. Repeat proced ure on opposite end.
