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13-17-609 Page 20
2-5
Unsheltered (outside) installations should be avoided whenever possible. Installation next to a heated
building where enough heat can be used to keep the compressor room above freezing will save many
complications in the operation and installation of the unit.
Refer to Engineering Data Sheet 13-9-411, available from an authorized Gardner Denver distributor, for
the advantages of using the heat recovered from rotary compressors. This heat recovery could easily
pay for an adequate shelter for the unit.
AUXILIARY AIR RECEIVER
- An auxiliary air receiver is not required if the piping system is large and
provides sufficient storage capacity to prevent rapid cycling. An adequate receiver capacity for the VST
units is 1/2 gallon for each cfm delivered by the compressor package.
MOISTURE SEPARATOR/TRAP
- Since the unit is equipped with a built-in aftercooler, a combination
moisture separator and drain valve are furnished with the unit.
CONTROL PIPING
- Control piping is not necessary since the Gardner Denver compressor package is
factory wired and piped for the control system specified. Control tubing for the air-cooled module has
been already covered under the
“Air-cooled Units” segment above.
INLET LINE
- Where an inlet line is used between the air filters and the compressor, it must be thoroughly
cleaned on the inside to prevent dirt or scale from entering the compressor. If welded construction is
used, the line must be shot blasted and cleaned to remove welding scale. In either case, the inlet line
must be coated internally by galvanizing or painting with a moisture and oil-proof sealing lacquer. Up to
ten (10) feet (3 meters) in length, the inlet line should be the full size of the inlet opening on the
compressor. If an extra-long line is necessary, the pipe size should be increased according to Inlet Line
Length Chart Figure 2-2
Accessibility for inlet air filter servicing must be considered when relocating the filters from the unit to a
remote location.
Length of Inlet Line
Diameter of Pipe Size
0 to 10 Feet (0 to 3 Meters)
Same as Compressor Inlet Opening
10 to 17 Feet (3 to 5 Meters)
One Size Larger Than Inlet Opening
17 to 38 Feet (5 to 11.5 Meters)
Two Sizes Larger Than Inlet Opening
Figure 2-2 – INLET LINE LENGTH
DISCHARGE SERVICE LINE
- The discharge service line connection of the Water Cooled compressor
package is on the roof area of the enclosure
– see Fig 1-2, page 10 for details. The discharge service
line connection on the air-cooled package is on the side of the air-cooled module - see Figure 1-6 and
Figure 1-7 pages 14 and 15 for details. The Gardner Denver compressor packages are inherently
isolated from the service line by their own minimum pressure/check valves. Installer or end user must
ensure that other compressors that are piped into a common pipe manifold with the Gardner Denver
compressor package are each provided with an isolation check valve. It is recommended that an
additional receiver be installed between the rotary screw and reciprocating compressors sharing a
common pipeline. Do not install another check valve in the unit
’s discharge line as operational upsets will
occur.