Minimum & Maximum Operating Conditions; Maximum Operating Pressure (Mop); Minimum Operating Pressures; Piping - Gardner Denver DGH Series Instruction Manual

4. Installation
4.3 Minimum & Maximum Operating Conditions
The compressed air supply to the dryer inlet should be checked
periodically to ensure that dryer design specifications are not
exceeded. Normally the compressor installation includes
intercoolers, aftercoolers, separators, receivers, or similar
equipment, which adequately pretreat the compressed air supply
in order to avoid excessively high air temperatures and liquid
slugging of downstream equipment.

4.4 Maximum Operating Pressure (MOP):

•
150 psig (10.5 kgf/cm
2
•
250 psig (17.6 kgf/cm
2
Refer to Dryer Serial Number Tag.
WARNING - Do not operate the dryer at pressures above the
maximum operating pressure shown on the serial number tag.
NOTE: Consult factory for applications requiring higher
maximum operating pressures.

4.5 Minimum Operating Pressures:

4.5.1 For 150 psig (17 .6 kgf/cm
•
60 psig (4.2 kgf/cm ) is the minimum operating pressure
2
for dryers operated on ISO classes 1, 2, 3, and 4.
4.5.2 For 250 psig (17 .6 kgf/cm
•
120 psig (8.44 kgf/cm
for dryers operated on ISO classes 1, 2, 3, and 4.
Refer to Dryer Serial Number Tag.
WARNING - Do not operate the dryer at pressures below the
minimum operating pressure shown on the serial number tag.
NOTE: Consult factory for applications requiring lower minimum
operating pressures.
4.6 Maximum Compressed Air Temperature at Dryer
Inlet:
•
140°F (60°C) for all models.
4.7 Ambient Temperatures:
4.7.1 Minimum Ambient Temperature
•
Standard units: 35°F (2°C)
•
Units with optional low ambient package: -20°F ( -29°C)
4.7.2 Maximum Ambient Temperature
•
120°F (49°C)
NOTE: If dryer is installed in ambients below 35°F (2°C), low
ambient protection requiring heat tracing and insulation of the
4. Installation
) is standard.
) is optional.
) MOP models -
2
) MOP models -
2
) is the minimum operating pressure
2
prefilter bowls, auto drains and/or sumps, and lower piping with
inlet switching and purge/repressurization valves is necessary
to prevent condensate from freezing. If installing heat tracing,
observe electrical class code requirements for type of duty
specified. Purge mufflers and their relief mechanisms must be
kept clear from snow and ice buildup that could prevent proper
discharge of compressed air.
4.8 Mounting
Install dryer on a level pad. Holes are provided in the dryer base
members for floor anchors.
NOTE: Floor anchors must be used if area is subject to vibration.

4.9 Piping

Inlet and Outlet connections
Observe locations of inlet and outlet connections as shown in
Figures 4-2 or 4-3 and connect inlet and outlet piping as
indicated.
NOTE: All piping must be supported so as not to bear on the
dryers or filters.
4.10 Isolation Valves
If isolation or bypass valves are installed, care must be used to
ensure that equipment is pressurized slowly. This is particularly
true if isolation valves are placed before and after pre and
afterfilters where rapid pressurization could cause excessive
pressure drop across filter elements.
NOTE: When quarter-turn valves (e.g. ball or butterfly valves)
are used for isolation of pressure components, care should be
taken to open or close valves slowly.
4.11 Electrical Connections
Refer to the appropriate controller sections for detailed
information on connections, ratings, and operation of the Level 1
or Level 2 Controller.
NOTE: Refer to the dryer serial number tag for allowable
voltages, frequency and power rating.
4.12 Provisions for Purge Exhaust
•
Purge exhaust must be routed through the factory supplied
mufflers or piped to a remote location.
•
Purge mufflers - If shipped separately, install purge exhaust
mufflers in the locations shown in Figures 4-2 or 4-3.
•
If purge exhaust is piped to a muffler located in a remote
location, choose a combination of diameters, lengths, and
turns that limits the additional pressure drop to 1 psid or
less.
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