Parker DTX 10 User manual

Heatless High Pressure
Desiccant Dryers
User Guide
Models DTX10 -DTX80

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DTX10 - DTX80 USER GUIDE
Introduction Letter
Dear Customer,
Let us take this opportunity to introduce our company.
Parker is an innovative manufacturer of industrial equipment for compressed air
systems.
Our product line includes natural gas dryers, fluid coolers, water separators, air filters,
refrigerated air dryers, and heatless and heat reactivated desiccant air dryers. Our
products can be found in all corners of the world.
No effort has been spared to provide a comprehensive instruction manual for the use
of the Parker Dryer. Information is given not only for the user, but also for the technical
personnel who may repair the dryer in the event that this is ever necessary. It is
recommended that all who will have responsibility for the dryer carefully read all sections
of this manual before commencing with the installation.
The most important step is for you as a customer is to call us first at
1-855-5TRYFAF if you are experiencing a problem with your dryer.
If there is a question regarding this manual or our warranty policies and procedures,
please call. We would be happy to speak with you.
Thank you for choosing Parker products.
Parker Service Department

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DTX10 - DTX80 USER GUIDE
Contents
1. Inspection and Installation 4
1.1 Inspection 4
1.2 Dryer Location 4
1.3 Installation 4
2. Safety and System Precautions 6
3. General Operation 6
4. Sequence of Operation 8
5. Start Up 9
6. Operational Notes 10
6.1 Variable Cycle Control 10
7. Shutdown Procedures 11
8. Demand Cycles 12
8.1 CycleLoc 12
8.2 Dryers Equipped with DDS 12
9. Maintenance Program 14
9.1 Desiccant Replacement 14
9.2 Inlet and Exhaust Valve Repair 15
10. Parts (general parts description) 16
11. Troubleshooting Guide 17
12. High Humidity 19
12.1 Principle of Operation 19
12.2 System Components 19
12.3 Calibration Procedure 19
12.4 Precautions, Limitations, and Hazards 19
13. Optional DDS 20
13.1 Quick-Start for Dryers Equipped with DDS 20
13.2 Design and Theory of Operation 20
13.3 Mounting the Probe 21
13.4 Probe to Analyzer Connection 21
13.5 Electrical Connection 21
13.6 Troubleshooting 21
13.7 DDS Display: 22
14. Optional Pre/After Filters 23
15. Warranty 25
Appendix - Spare Parts 27
Appendix - Drawings 28

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DTX10 - DTX80 USER GUIDE
1. Inspection and Installation
PRIOR TO INSTALLATION OR START-UP OF DRYER, THIS ENTIRE MANUAL SHOULD BE READ
AND UNDERSTOOD.
1.1 Inspection
All Dryers are tested and inspected at the factory prior to shipping. Inspect the dryer carefully upon
arrival and note any damage on the freight bill. Uncrate and inspect for concealed damage. File
claims with the carrier immediately and notify the manufacturer service department.
1.2 Dryer Location
Locate the dryer in an area accessible for maintenance. The dryer should have minimum 36”
clearance on all sides. See dimensional print for specic clearance requirements. The area should be
clean, well lighted and have a level, vibration free oor. For standard applications, ambient temperatures
should range between 35°F and 100°F. Consult the factory concerning applications outside this
temperature range.
1.3 Installation
(See typical installation drawing)
NOTE: All piping and electrical connections should be checked to insure they have maintained their
integrity during shipping and installation.
WARNING! Incorrect installation may void warranty! IMPORTANT! Sizes above 1500 SCFM require eld
desiccant charging. Units above 1500 are shipped empty due to weight constraints.
- Coalescing Pre-Filter with auto drain must be installed.
- Standard dryers are designed for 100°F inlet temperature or less.
- Ambient temperatures should be between 35°F and 100ºF.
- Dryer should be located in an area accessible for maintenance.
- Location should be clean, cool, with a level, vibration free oor.
- Location of receiver may vary depending on particular conditions and type of compressor.
- Auto drains are required when receiver is mounted up- stream of dryer.
Make the following connections:
1. Inlet piping, including an isolation valve.
2. Outlet piping, including an isolation valve.
3. Coalescing Pre-Filter and Particulate After-lter.
IMPORTANT! Desiccant dryers are designed to remove water VAPOR only!
Locate the coalescing lter as close to the dryer as possible. The air to be dried must pass through a
Coalescing Pre-Filter for removal of entrained condensate and oil to prevent fouling of the desiccant.
Liquid condensate entering the bed will lead to overloading of the dryer, poor dew point performance,
and rapid deterioration of the desiccant. Oil entering the desiccant bed may permanently reduce the
capacity of the desiccant.
A Particulate After-lter should be provided to prevent desiccant dust from traveling down stream.
Desiccant dust may cause contamination and excessive wear to equipment. Differential pressure
indicators should be installed on lters for monitoring of elements. A particulate lter before the dryer
and adsorber after the dryer are optional.
4. Auto Drain on Pre-Filter. An Automatic Drain is required on the Pre-Filter and all other upstream
collection points to remove condensate.
5. IMPORTANT! Bypass piping is necessary. A bubble tight valve should be used for bypass
around lters and dryer for servicing.

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DTX10 - DTX80 USER GUIDE
6. Make required electrical connections to control box. Refer to applicable drawings.
NOTE: Customer to provide short circuit protection for dryer.
7. Access ports should be provided upstream and downstream of the dryer for dew point,
pressure, and temperature checks. Periodic checking of the dew point just downstream
of the dryer is the best indication of whether the dryer is performing as expected. A High
Humidity Alarm or DDS are available as options.
8. All piping should be adequately supported and at least of equal size to the dryer connections.
9. To reduce maintenance and increase dryer efciency, the exhaust ports can be piped to
a location where the exhaust mufers are not required. The piping MUST NOT create
any back pressure on the regenerating tower and must be up-sized accordingly. It is
recommended that the exhausts be piped separately for ease of troubleshooting
and maintenance.
Before any attempt is made to operate the dryer, the operator should thoroughly read and
understand this instruction manual. Improper operation will cause poor results from
the dryer.
RECOMMENDED INSTALLATION
CLEAN DRY, CONTAMINANT FREE AIR
MINIMUM REQUIREMENTS
ROTARY
OR CENTRIFUGAL
COMPRESSOR
AFTER-
COOLER
SEPARATOR
AD AD
C
AIR
DRYER
COALESCING
Pre-lter
PARTICULATE
FILTER
AIR
RECEIVER
F
BY-PASS PIPING
BY-PASS VALVE MUST BE BUBBLE TIGHT
IDEAL INSTALLATION
ROTARY
OR CENTRIFUGAL
COMPRESSOR
AFTER-
COOLER
SEPARATOR
AD AD
C
AIR
DRYER
FILTERS FILTERS
AIR
RECEIVER
F
BY-PASS PIPING (OPTIONAL)
BY-PASS VALVE MUST BE BUBBLE TIGHT
AD
FA
T
T
D
KEY
AD = AUTOMATIC DRAIN
F = PARTICULATE FILTER
C = COALESCING FILTER
A = ADSORBING FILTER
= TEMPERATURE INDICATOR
= DEWPOINT INDICATOR/CONTROLLER
= DIFFERENTIAL PRESSURE INDICATOR
T
D

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DTX10 - DTX80 USER GUIDE
2. Safety and System Precautions
• Use EXTREME CAUTION when working in the vicinity of the dryer.
• Relieve pressure before servicing dryer or associated equipment.
• Disconnect power before servicing dryer.
• Use ear and eye protection when in the vicinity of the dryer or exhaust ports, especially if the dryer is
being operated without mufers. Even when mufers are used, a tower blowing down to atmosphere
will raise particles, create more noise than during “normal” operation and may startle an individual not
used to this portion of the operation.
• In the case of an overpressure situation there is a safety relief valve on each tower designed to protect
the equipment. If these end up pointed in a hazardous direction after dryer installation, they should be
piped to safe location.
• Automatic or manual drain valves will eject water, oil, particulates and air under partial pressure when
operated. proper precautions must be taken.
• Condensate drainage from compressed air systems may contain oil or other contaminants. Follow all
applicable regulations for safe handling and disposal.
• Various component failures could cause large air loss and subsequent pressure drop. Preventive
maintenance should be performed to reduce the likelihood of this. If this occurs, bypass the dryer
immediately to restore ow and pressure.
• Activated Alumina dust is considered a nuisance dust. Proper precautions should be taken when
handling desiccant. For more information and for other types of desiccant, refer to applicable
Material Safety Data Sheet. For disposal of used desiccant refer to the applicable regulations.
NOTE: Desiccant contaminated with oil or other foreign substances may be covered under disposal
regulations for the contaminant.
Desiccant dryers work on the principle of adsorption. Adsorption is the process of removing water VAPOR
from the air to be dried. All condensed liquid water should be removed from the inlet air stream prior to
reaching the dryer by suitable separators, traps, lters, and drains. The dryer can not be burdened with
liquid condensate carry-over.
All desiccants are adversely affected by oil, aerosols, dirt, rust, scale or liquid water. Effective pre-ltration
in conjunction with automatic condensate drainage is a must for proper dew point suppression and long
desiccant life.
The saturated inlet air is alternately cycled through each of the two desiccant beds. One bed is “on-line” at
full line pressure and ow, adsorbing water vapor from the saturated inlet air. This is the drying bed.
The other bed is “off-line” at atmospheric pressure (0 PSIG) being regenerated by a depressurized portion
of the dried outlet air (purge air). This is the regenerating bed.
The quantity of purge air for a standard pressure dryer is approximately 5% of inlet design ow. This air is
taken from the dry air outlet, directed through the purge ow controls, purge check valves, desiccant bed,
and nally exhausted to atmosphere to accomplish regeneration. Purge air consumption is typically the
largest cost involved with operating a heatless desiccant air dryer. (Purge air is “non-recoverable” and the
air system in question must be designed to allow for this usage.)
IMPORTANT! The dryer is designed to remove only water vapor. You might see a small amount of
condensate forming at the exhaust due to the Joule-Thomson cooling effect created by the
depressurizing air.
3. General Operation

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DTX10 - DTX80 USER GUIDE
Prior to switching a freshly regenerated bed “on-line” to become the drying bed, it must be slowly
pressurized from atmospheric pressure to line pressure. This step is called repressurization.
Repressurization prevents bed uidization (lifting) and associated dusting.
Following repressurization, the beds switch functions with the fresh bed now drying and the saturated bed
being regenerated.
Note that one bed is always “on-line” drying. Also note that purge air is always being consumed except
during repressurization.
This cycle will continue automatically unless the dryer is shut down, operated in the CycleLoc mode or
equipped with a DDS.
Dryer Outlet Flow
Dryer outlet ow is equal to the dryer inlet ow minus the purge ow.
Air
Out
Air
In
Main
Exhaust
DTX Series Flow Schematic
MODEL CAPACITY PSI CFM COLOR SIZE DES/TOWER IN/OUT CON.
DTX 10 50 no gauge 2.5 BLUE 3/32" 12 3/8" NPT
DTX 20 95 no gauge 5 BLUE 3/32" 15 1/2" NPT
DTX 30 200 110 10 BLUE 3/32" 37 3/4" NPT
DTX 40 350 225 18 BLUE 3/32" 75 1" NPT
DTX 50 550 185 28 GOLD 1/8" 120 1 1/2" NPT
DTX 60 800 275 40 GOLD 1/8" 150 1 1/2" NPT
DTX 80 1400 200 70 GREEN 3/16" 300 2" NPT
MODEL CAPACITY PSI CFM COLOR SIZE DES/TOWER IN/OUT CON.
DTX 10 75 - 2.3 BLUE 3/32" 12 3/8" NPT
DTX 20 130 - 4 BLUE 3/32" 15 1/2" NPT
DTX 30 250 90 8 BLUE 3/32" 37 3/4" NPT
DTX 40 400 135 12 BLUE 3/32" 75 1" NPT
DTX 50 750 275 23 BLUE 3/32" 120 1 1/2" NPT
DTX 60 1000 375 30 BLUE 3/32" 150 1 1/2" NPT
DTX 80 1800 375 54 GOLD 1/8” 300 2" NPT
High Pressure 500 MAWP Technical Specs
High Pressure 1000 MAWP Technical Specs

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DTX10 - DTX80 USER GUIDE
4. Sequence of Operation
The sequence is controlled by a Solid State Timing and Relay circuit (Sequence Annunciator) which in turn
controls ve electric solenoid valves. The rst four are 3-Way Normally Closed Valves, which supply control
air to operate air operated switching inlet and exhaust valves. The Inlet Valves are Normally Open and are
closed by supplying dry control air to the valve actuator. The Exhaust Valves are Normally Closed and are
closed by supplying dry control air to the valve actuator. The fth solenoid is the repressurization valve.
There are also four mechanical check valves, two outlet and two purge, that allow for proper air ow.
STEP 1- LEFT DRYING; RIGHT REGENERATING
SOLENOID #1 is de-energized sending no air to Exhaust Valve #1 (left side). Exhaust Valve #1 is closed.
SOLENOID #2 is de-energized sending no air to Inlet Valve
#1 (left side). Inlet Valve #1 is open. All of the wet inlet air is owing through Inlet Valve #1. It is dried as it
passes through the left tower desiccant bed and exits out the left side Outlet Check Valve to the dryer out-
let. The left tower is the Drying tower and the associated pressure gauge should read line pressure,.
At the same time SOLENOID #3 is energized sending a signal to Inlet Valve #2 (right side). Inlet Valve #2 is
closed, preventing inlet air ow through the right tower.
SOLENOID #4 is energized sending a signal to Exhaust Valve #2 (right side). Exhaust Valve #2 is open.
(NOTE: When exhaust valve rst opens, the associated tower will depressurize from line pressure to atmo-
spheric pressure.) Purge air will now ow from the dry air outlet through the Purge Adjusting valve, Purge
Orice and the right hand Purge Check Valve. This purge air then proceeds through the right tower near
atmospheric pressure, removing the moisture and exiting the right hand Exhaust Valve and Mufer in vapor
form (at no time should the dryer expel any signicant amount of liquid water from the mufer; this is a sure
sign of trouble in the system). The right tower is the regenerating tower, the associated pressure gauge
should read “0” PSIG.
SOLENOID #5 is de-energized and closed.
STEP 2 - LEFT DRYING, RIGHT REPRESSURIZING
While the left tower is still drying, Solenoid #4 will de- energize, relieving the control air signal on the right
exhaust valve, returning that valve to its normally closed state. Closing this valve keeps air in the tower, al-
lowing the depressurized part of the dryer to build up pressure or “repressurize”. At the same time Solenoid
#5 is energized and opened, providing additional air to the tank coming from the purge line to ensure full
repressurization of the dryer. Prior to switching towers, all of the gauges should equalize to line pressure.
STEP 3 - LEFT REGENERATING, RIGHT DRYING
Step 3 is the reverse of step 1. Solenoid #1 is energized, providing control air to and opening the left ex-
haust valve.
Solenoid #2 is energized, providing control air to and closing the left inlet valve. Solenoid #3 and #4 are
de-energized. Thus the right inlet is open, and the right exhaust is closed. All the wet air is now owing
through the right tower and is being dried at line pressure. The left tower is being regenerated at
atmospheric pressure. Solenoid #5 is de- energized and closed.
STEP 4 - LEFT REPRESSURIZING, RIGHT DRYING
Step 4 is the reverse of Step 2. Solenoid #1 de-energizes, allowing the left exhaust valve to close and al-
lowing the dryer to repressurize. In addition, Solenoid #5 energizes providing additional air for repressuriza-
tion.
NOTE: The Purge Gauge (middle) should read purge pressure, except during repressurization. Purge pres-
sure for standard inlet design conditions is listed on page 4. For other than standard or design conditions
consult the factory.

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DTX10 - DTX80 USER GUIDE
5. Start Up
Please read and understand the entire manual before operating the dryer.
Check and read over wiring diagrams that pertain to your unit and make sure the correct power supply is connected,
but do not energize circuit at this time. Provide proper short circuit protection. Follow all applicable codes.
If you do NOT want the dryer to cycle automatically when energized, close the control air isolation valve. If the
system has already been pressurized, bleed off the control air pressure by opening the knob on the bottom of the
control air lter and reclosing.
Before starting the dryer your compressor should be running, your air system pressurized and the dryer bypassed
and not yet pressurized.
SLOWLY open the inlet isolation valve admitting compressed air to the dryer. It is important to pressurize the dryer
slowly to prevent uidization of the desiccant bed. The dryer outlet isolation valve should be closed at this time.
SLOWLY open dryer outlet isolation valve. At this point all valves are in “normal” positions; air is owing through
both towers and downstream.
Close the dryer bypass valve. Bypass valves must be bubble tight to prevent moisture from migrating around the
dryer and contaminating the dry air outlet.
It is required that the dryer be started without the mufers installed. This will expedite removal of excess desiccant
dust and prevent premature clogging of the exhaust mufers.
CAUTION: USE EAR AND EYE PROTECTION WHEN OPERATING DRYER WITHOUT MUFFLERS. EXCESSIVE
NOISE WILL BE CREATED. DUST AND PARTICLES FROM THE SURROUNDING AREA MAY BECOME
AIRBORNE. OPERATION WITHOUT MUFFLERS EXCEEDS OSHA LIMITS.
Check the Variable Cycle Control setting. It should normally be set at the standard 10 minute, 100% load.
Energize the electrical circuit. If the control air valve is open the dryer will begin to cycle.
If the control air valve is closed, open it to begin the dryer cycle. At this point one tower will exhaust its air to
atmosphere. See “CAUTION” statement above.
Check and adjust the setting of the purge pressure indicator or purge ow meter in accordance with the
specications for your dryer. Normally, purge ow is approximately 15% of design ow for the dryer. Note that even
if you are operating under a light load the purge can not be reduced if you are operating in the DDS or CycleLoc
modes, or a xed timed cycle other than the standard 10 minute, 100% load cycle.

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DTX10 - DTX80 USER GUIDE
6. Operational Notes
Never service the dryer or lters without rst relieving pressure.
Check all air connections for leaks and tighten as required. Downstream air leaks will affect dew point.
Bypass air leaks will affect dew point. Only soft seat bypass valves may be used.
Dryer will not perform without proper pre-ltration, condensate drainage, and purge ow. Dryers may
require up to 48 hours of operation to reach normal operating dew points. Therefore, indicators and/or
alarms should not be recognized until that time. Applications requiring dew points lower than -40°F, or with
nonstandard operating conditions, may require additional time to reach equilibrium.
Exhaust valves and/or exhaust mufers may have to be cleaned due to dusting in shipping and start-up.
A desiccant dryer should never be suddenly pressurized or depressurized. This will cause uidizing and
dusting of the desiccant bed.
After start-up, some dusting may occur. This will diminish with time. Some dusting may occur with normal
operation. The Exhaust Mufers should be cleaned regularly and an After-lter should be used.
Flow direction is Upow Drying - Downow Purge. Switching Failure Alarm is optional and the dryer must
be operating over 70 PSI for proper function of the alarm. Dryer valving is “fail-safe” on power loss. This
means the inlet valves open and exhaust valves close, allowing system to remain pressurized and air to
ow through both towers, and down stream.
The standard dryer has been designed for drying service to 500 PSIG.
The dryer must repressurize before switching.
6.1 Variable Cycle Control
The heatless dryer is equipped with Variable Cycle Control. This control allows for easy adjustment
to meet varying plant loading. By using this control, the dryer can be set to one of two standard
xed time cycles, a) standard 100% load (10 minute), b) short cycle -80°F dew point (5 minute).
Complete cycle times are given below.
Cycle Times (time in minutes: seconds)
The short cycle will provide a -40°F to - 80°F dew point when operating at or below design
conditions. Always set the purge as if you had a full inlet ow when using these cycles. The cycles
automatically compensate for the light loading; there is no need to turn the purge down.
TOTAL
TIME
PER TOWER TIME
CYCLE DRYING REGEN. REPRESS.
100% Load 10:00 5:00 4:15 0:45
75% Load 15:00 7:30 4:15 3:15
50% Load 20:00 10:00 4:15 5:45
Short (-80) 5:00 2:00 2:00 0:30

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DTX10 - DTX80 USER GUIDE
7. Shutdown Procedures
Isolation
1. Allow dryer to reach repressurization step and fully repressurize
2. While fully repressurized, remove power from the dryer by turning off disconnect.
3. Open bypass pipe.
4. Close outlet isolation valve.
5. Close inlet isolation valve.
Depressurization
1. Open bypass piping.
2. Close outlet isolation valve.
3. Close inlet isolation.
4. Allow dryer to run. The normal cycle will allow both tanks to blow down and depressurize.
5. Disconnect power.
6. With the “Basic Filter Package” dryers, open manual ball valves on lters to allow full
depressurization. Leave ball valves on lters open while servicing. Without the “Basic Filter
Package”, close control air lter off. Remove nylon tubing from control air lter or any control
solenoid. Reopen control air lter to fully depressurize. Leave control tubing off while servicing.
To restart, follow “Start-Up” procedure. IMPORTANT! Always remove all pressure and disconnect
all power before servicing the dryer.
IMPORTANT! If DDS is installed and the dryer will be out of service for an extended period of time,
remove the probe and store in a safe, dry location. The probe will be damaged if exposed to prolonged
periods of saturated conditions.

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DTX10 - DTX80 USER GUIDE
8. Demand Cycles
CycleLoc and DDS are demand cycles available for any heatless dryer. CycleLoc is standard on all heatless
dryers. DDS is an option that needs to be purchased. These cycles offer improved operating efciency over
xed time cycles for applications requiring a -40°F dew point and that will see lighter than design moisture
loading. Demand cycles reduce total purge consumption and thus reduce energy usage by tailoring the
cycle to actual loading, vs., xed cycles which assume 100% design loading. Demand cycles can not
accommodate for heavier than design loading. It can not shorten the xed cycle, only lengthen it.
8.1 CycleLoc
The CycleLoc feature is built in to every model. It can be used to interface the dryer with the
compressor. The dryer must be able to handle at least full ow of the compressor and the receiver
should ideally be located downstream of the dryer. A dry (unpowered) contact closure across
the CycleLoc terminals on the Sequence Annunciator will cause the dryer to immediately pause
its cycle & stop purging. The contact closure needs to correlate with the compressor stopped
or unloaded. When the contact opens the dryer cycle will resume where it left off. Typically a
contact on the compressor pressure control is utilized. If a dry normally open (with compressor
running) contact is not available, an auxiliary relay will need to be added. The jumper JP1 must be
installed for correct CycleLoc operation. Please consult the factory for more information.
8.2 Dryers Equipped with DDS
The DDS is a digital display. The sensor is a thin lm gold aluminum oxide design. The DDS
observes the outlet pressure dew point of the dryer and digitally displays it. The DDS feature
tailors the dryer cycle to actual loading conditions, minimizing energy usage. Without the Dew
Point Monitor, the cycle is xed and “worst case” design conditions are assumed.
The Demand Cycle is accomplished by providing a discrete dry contact closure across the
CycleLoc terminals on the Sequence Annunciator. The Variable Cycle Control Switch must be set
to 100% load setting for the DDS to work. If the dryer is maintaining a good dew point AFTER
the rst ve minutes of drying, the DDS will override the xed cycle and keep the current tower
“on-line” until it is saturated to design loading (switch point value), usually -40°F. If this occurs, the
“off- line” bed which has just nished being regenerated will repressurize and be ready to go “on-
line”. The CycleLoc light on the Sequence Annunciator and the DDS will be on at this time. Once
the dew point degrades to the switch point value, the freshly regenerated bed will go “on-line”,
and the saturated bed will depressurize and begin regeneration. Note that the DDS cannot shorten
the cycle. The drying tower will always undergo a design regeneration cycle of 4 minutes and 15
seconds. The DDS can only compensate for under-loading, not overloading conditions.
If there is any error with the DDS or probe, the DDS will not function. There is also a DDS On/Off
switch located in the control enclosure. If this switch is turned off, the dryer will operate in the
xed time cycle. The DDS will continue to display dew point. The DDS is fully programmed and
wired at the factory if ordered with the dryer.
For dryer start-up, all that is normally required is sensor installation. The sensor should be installed
after dryer has been allowed to purge the initial dusting caused by transportation or lling. The
probe isolation valve should be fully opened after installation to allow operations at full line
pressure for correct reading of pressure dew point. A coil of capillary tubing is provided to allow
a small sample ow over the sensor and prevent ambient moisture from inltrating the system.
Check the bleed periodically to ensure it is not clogged.
Following sensor installation, allow the sensor to stabilize at the line pressure for four hours prior
to attaching the sensor cable.
Failure to follow the above precautions may result in sensor failure not covered by warranty.
Please note that upon installation the sensor will be saturated at atmospheric conditions. Even if
the dryer is producing a good dew point, it will not be indicated immediately as it will take a period

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DTX10 - DTX80 USER GUIDE
of time for the sensor to dry out and come to equilibrium with the system.
The sensor will also become saturated to atmospheric conditions if the air system is shut down
and allowed to depressurize. Upon restart of the system, the dew point may appear to be poor,
even though the dryer may be producing clean, dry air.
Although the probe can be exposed to occasional, brief periods of liquid saturation, it can not
be exposed to continuous wet conditions. If your dryer is over loaded and saturated, or if it will
be shut down for an extended period of time; remove or isolate the probe until the problem is
resolved. Refer to the separate DDS section for more detailed information.
IMPORTANT! Demand Control Cycles can not be used together! Please consult factory to ensure
proper use of any of the nonstandard cycles.

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DTX10 - DTX80 USER GUIDE
9. Maintenance Program
Daily
1. Check dew point or humidity level if instrumentation is available. Any difculty with the dryer will result in
poor dewpoint performance.
2. Check for correct purge setting and air ow from purge exhaust.
3. Check gauge readings and sequence of operation through complete cycle.
4. Check auto drain operation on pre-lter, separator and receiver. A manual drain valve installed (in
addition to the automatic drain) at these points will ease checking of the automatic drains.
5. Ensure there is no back pressure in the regenerating tower.
Weekly
1. Check differential pressure across pre-lter and after-lter elements. Replace if required.
2. Check and maintain operating conditions; pressure, ow, and temperature within the design parameters
of the dryer.
Semi-Annually
1. Inspect desiccant for physical condition. Desiccant from a freshly regenerated bed should be white, dry
to touch and of consistent size and shape.
2. Check and clean mufers. This may be required often under certain conditions or if back pressure
develops. Mufers can be cleaned by blowing backwards through them with clean, dry air. Mufers may
require replacement if severely clogged, or after a few cleanings.
3. Replace pre-lter and after-lter elements.
4. Clean automatic drain.
5. Replace control air lter element.
6. Check and slowdown safety valves. Refer to manufacturer’s instructions.
7. Clean dryer.
Annually
1. Inspect and rebuild inlet and exhaust valves.
2. Return DDS probe and chip for recalibration, if applicable.
9.1 Desiccant Replacement
CAUTION: Activated Alumina Desiccant dust is considered a nuisance dust. Proper precautions
should be taken. Refer to “Material Safety Data Sheet”.
1. Remove pressure and power from dryer.
2. Open drain ports on bottom of tanks.

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DTX10 - DTX80 USER GUIDE
3. Catch desiccant in suitable container. Close drain ports and open top ll ports.
4. Rell with recommended type, size and quantity of desiccant. Wrap sides of the
chambers while lling so desiccant will pack tightly. Some settling may be required to t
specied amount in tank. One tank size may be used for multiple models, do not be
concerned if tank is not full.
5. Consult Material Safety Data Sheet and all applicable regulations for disposal of
desiccant. Disposal of desiccant contaminated with oil or other substance may require
different procedures than desiccant replaced strictly due to aging.
NOTE: Use only manufacturer supplied desiccant which is a high capacity, high quality desiccant
designed and sized for the dryers.
9.2 Inlet and Exhaust Valve Repair
1. Shutdown the dryer as described in this manual. Remove pressure from the dryer Make
certain there are no “pockets” of pressure isolated by various valves. Open the bleed
valve on the bottom of the control air lter bowl.
2. Loosen the compression tting attaching the control tubing to the valve body. Carefully
move the tubing aside.
3. Disassemble valve to clean or repair. Repair kits are available for most valves.
4. Reassembly is reverse of disassembly. Replace all O-rings, gaskets and components.

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DTX10 - DTX80 USER GUIDE
10. Parts (general parts description)
A. DESICCANT - An adsorbent used for drying air or gases. Proper quantity, size and type are necessary.
B. INLET VALVE - Normally Open Air Operated Switching Valves used to direct the air ow through the
towers.
C. EXHAUST VALVE - Normally Closed Air Operated Switching valves used to exhaust purge air, hold air in
tower on line, and exhaust air from tower ready to be regenerated.
D. OUTLET AND PURGE CHECK VALVES - Valves that allow full ow in one direction and no ow in the
other are used in conjunction with the inlet and exhaust valve to accomplish desired ow of process
and purge air.
E. SAFETY RELIEF VALVES - Furnished on each tower to protect the vessels from overpressure
situations. Setting is indicated on valve.
F. PURGE EXHAUST MUFFLER - Furnished to reduce exhaust noise during purge and blow down for
personnel protection and to comply with OSHA standards. Mufers offer no benet to the operation
of the dryer and are a maintenance concern. Consideration should be given to locating the exhaust in
an area where mufers would not be required.
G. PURGE CONTROL REGULATOR OR VALVE - Furnished to adjust and regulate purge ow for
regeneration.
H. SOLID STATE CONTROLLER/SEQUENCE ANNUNCIATOR PANEL - Furnished for cycle control.
Outputs operate 5 electric solenoid valves. Provides for Variable Cycle Control. Provides interface with
optional DDS and has integral lights to provide visual cycle indication. Has built-in automatic drain
control. All hard wired connections, including eld power connection, are made to this board.
I. TOWER PRESSURE GAUGES - Furnished to read pressure in each tower. On-line tower should read
line pressure, regenerating tower should read “0” PSIG.
J. PURGE FLOW INDICATOR (center gauge) - Furnished to indicate and monitor proper purge ow.
K. CONTROL SOLENOIDS - (4) 3-way normally closed electric solenoid valves, operated by the solid
state controller, that in turn provide a control air signal to operate the inlet and exhaust valves.
L. REPRESSURIZATION SOLENOID (Variable Cycle Control Bypass) - A solenoid valve provided to
ensure tower repressurization before switching, even at low ows.
M. CONTROL AIR FILTERS - Filters control air, which is taken from the dryer outlet, to protect the control
solenoids from desiccant dust. Also protects DDS Probe where applicable.

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DTX10 - DTX80 USER GUIDE
11. Troubleshooting Guide
Exhaust Valve on Drying or
Repressurizing Tower Leaking
1. Valve dirty Clean valve
2. Defective diaphragms or O-rings Repair or replace
3. Leaking control solenoid Repair or replace
Excessive Pressure Drop 1. Pre-lter dirty Replace element
2. After-lter dirty Replace element
3. Desiccant dirty Replace desiccant
Unit Does Not Fully Repressurize 1. Purge rate too low Adjust purge
2. Exhaust valves leaking See above
3. Repressurization solenoid faulty Replace solenoid
4. Purge or repressurization orice
plugged
NOTE - On newer units, orice is a
different color than the rest of the
unit
Back Pressure in Regenerating
Tower
1. Clogged mufers Clean, repair or replace
2. Check valves leaking Clean, repair or replace
3. Purge ow too high Adjust
4. No output from controller Replace fuse or controller
Inlet or Exhaust Valves not
functioning
1. Bad diaphragms or O-rings Rebuild valves available kits or
replace
2. No control air See below
3. Control solenoids defective Repair or replace
4. No output from controller Repair or replace
No Control Air at Inlet or Exhaust
Valves
1. Control air shutoff valve closed Open
2. Control air lter dirty Replace Element
3. Leak in control air tubing Repair
4. Control solenoid defective Repair or replace
5. No output from controller Replace fuse or controller
Constant Bleed From Control
Solenoid Top Exhaust Port
1. Associated inlet or exhaust vavle
defective
Rebuild or replace
2. Dirty or defective control solenoid Clean or replace
Constant Bleed From Vent On
Inlet
1. Defective diaphragms or O-rings Rebuild or replace
Exhaust Valve on Drying or
Repressurizing Tower Leaking
1. Valve dirty Clean valve
2. Defective diaphragms or O-rings Repair or replace
3. Leaking control solenoid Repair or replace
Excessive Pressure Drop 1. Pre-lter dirty Replace element
2. After-lter dirty Replace element
3. Desiccant dirty Replace desiccant
Unit Does Not Fully Repressurize 1. Purge rate too low Adjust purge
2. Exhaust valves leaking See above
3. Repressurization solenoid faulty Replace solenoid
4. Purge or repressurization orice
plugged
NOTE - On newer units, orice is a
different color than the rest of the
unit
Back Pressure in Regenerating
Tower
1. Clogged mufers Clean, repair or replace
2. Check valves leaking Clean, repair or replace
3. Purge ow too high Adjust
4. No output from controller Replace fuse or controller

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DTX10 - DTX80 USER GUIDE
Inlet or Exhaust Valves not
functioning
1. Bad diaphragms or O-rings Rebuild valves available kits or
replace
2. No control air See below
3. Control solenoids defective Repair or replace
4. No output from controller Repair or replace
No Control Air at Inlet or Exhaust
Valves
1. Control air shutoff valve closed Open
2. Control air lter dirty Replace Element
3. Leak in control air tubing Repair
4. Control solenoid defective Repair or replace
5. No output from controller Replace fuse or controller
Constant Bleed From Control
Solenoid Top Exhaust Port
1. Associated inlet or exhaust vavle
defective
Rebuild or replace
2. Dirty or defective control solenoid Clean or replace
Constant Bleed From Vent On
Inlet
1. Defective diaphragms or O-rings Rebuild or replace

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DTX10 - DTX80 USER GUIDE
12. High Humidity
12.1 Principle of Operation
The High Humidity Alarm (HHA) are circuits designed to function in conjunction with a Hygrosensor to
provide on/off control for compressed air dryers. The HHA can also provide an alarm when humidity
conditions exceed or go below a xed setpoint.
Operation of the controller is based on relay actuation at a predetermined resistance value. The
resistance of the humidity sensor (a Dunmore-type lithium chloride element) varies inversely proportional
to the relative humidity to which it is exposed. The controller supplies a constant excitation voltage
to the sensor and the change in resistance is measured. When the relative humidity reaches the
selected setpoint (-20°F, -29°C), the controller detects the corresponding resistance and activates a
single pole, double throw relay.
The controller is set to activate at a predetermined resistance value by using a setplug whose
resistance corresponds to the sensor resistance at a particular relative humidity condition (-20°F).
12.2 System Components
POWER: 12-/220 VAC + 10%, 50-60Hz, 1 Watt DIMENSIONS: PC Board 3.5 x 2.75 x 1.1 inches
OPERATING TEMPERATURE: + 15°F (-9.4°C) to 140°F(60°C) STORAGE TEMPERATURE: -40°F (-40°C)
to +200°F (93°C).
CAUTION! HHA IS POWERED UP DURING THIS PROCEDURE. USE CAUTION NOT TO TOUCH
LIVE EXPOSED TERMINALS.
12.3 Calibration Procedure
1. Remove the sensor input terminals and replace it with the appropriate setplug.
2. Adjust potentiometer P1 to the midpoint between the relay “pull-in” and “drop-out”.
3. Replace the setplug with the sensor. The unit is now ready for operation.
12.4 Precautions, Limitations, and Hazards
The HHA Controller uses 115 VAC. Avoid contact with exposed terminals when performing set
point adjustment.
Never test the sensor with an ohmmeter or other DC measuring device. To do so will permanently
damage the sensor.
Do not expose sensors to humidity’s at which condensation is likely to occur, nor to sprays or water
droplets in ducts and air exhausts.
Do not expose sensors to air stream carrying dust, soot, or other containments, unless properly
protected by bafe, 200 by 200 mesh screen, cellophane, or tissue paper wrap to prevent impingement
of particles on the sensing surfaces.

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DTX10 - DTX80 USER GUIDE
13. Optional DDS
13.1 Quick-Start for Dryers Equipped with DDS
The following steps are all that is normally required for start-up of dryers equipped with the DDS System.
Refer to the remainder of this manual for more detailed information on DDS Operation.
Please read entire Dryer Manual before proceeding.
1. The unit is prewired to the dryer at the factory with the exception of the probe to cable
connection at this time.
2. Purge the sample line of any desiccant dust by opening isolation valve. Use caution as
pressurized air and dust will blowout off open port.
3. Close isolation valve. Install the probe in the 1/2” SAE port provided. Hand tighten the nut,
and then using a wrench tighten the nut another turn and a half.
4. Slowly open the isolation valve to the full open position. It is imperative that the isolation
valve be fully open so that the DDS reads pressure dew point. The sample line is tted
with coiled capillary tubing to control the sample air ow. There must be continuous ow to
obtain an accurate reading.
5. Following exposure of probe to line pressure, allow it to stabilize for 4 hours prior to connecting
the probe cable. Failure to do so may cause premature failure not covered by warranty.
6. After 4 hours connect the probe to the analyzer via the cable provided.
7. The probe and dryer system may require 48 hours or more to reach desired dew point on
initial or subsequent start-ups. High humidity alarms should be disregarded until this time.
8. The unit is normally factory set for -40°F (-40°C) switching and -20°F (-29°C) high
humidity alarm.
9. Dry contacts rated at 120/250 VAG, 2.5 amps are provided for remote annunciation of high
humidity alarm. A linear 4 to 20mA output corresponding to dew point is also provided.
10. Both the switching and high humidity relays are fail-safe. In the event of probe or electronics
failure, the dryer will switch to the xed cycle, the high humidity alarm will activate, and a
diagnostic code will ash on the digital display.
11. Although the probe can be exposed to brief periods of liquid saturation, it can not be exposed
to continuous wet conditions. Remove probe to dry location if these conditions exist.
It is recommended that the probe be returned to the factory once a year for recalibration to standard
gases in order to maintain accuracy. Contact factory for further information.
13.2 Design and Theory of Operation
The DDS is a microprocessor controlled Pressure Dew Point (PDP) analyzer. The DDS
consists of a gold/aluminum oxide sensor probe and an electronics module. The microprocessor
calculates moisture (PDP) that is compensated for temperature and pressure and controls the switching
and alarm set points.
Total dew point control can be obtained with the switching relay, alarm relays, and an optional linear,
isolated 4 to 20mA output corresponding to the PDP.