Page 1
P/N 32-0272 rev B
INSTALLATION, OPERATION, & MAINTENANCE INSTRUCTIONS
FOR
SINGLE TOWER
COMPRESSED AIR DRYER
MODELS
D-12 through D-36
JUNE 2002
WARNING
DO NOT REMOVE, REPAIR, OR REPLACE ANY ITEM ON THE
DRYER WHILE IT IS UNDER PRESSURE. DEPRESSURIZE THE
DRYER COMPLETELY BEFORE STARTING INSTALLATION AND/
OR MAINTENANCE PROCEDURES. SERIOUS PERSONAL
INJURY MAY RESULT IF THESE SAFETY RULES ARE NOT
FOLLOWED.
DO NOT OPERATE THIS PRESSURE VESSEL ABOVE MAXIMUM
WORKING PRESSURE (MWP) AT MAXIMUM OPERATING
TEMPERATURE (OF) AS SHOWN ON THE ASME DATA PLATE.
THIS ASME CODE VESSEL MUST BE PROTECTED BY A
PRESSURE RELIEF VALVE. Refer to OSHA 1910.169 Par. b,
Sub. Par (3) and ASME Boiler and Pressure Vessel Code,
Section VIII, Division 1, UG-125 through UG-136. Also check
government regulations, i.e., state and local codes.
DO NOT WELD, GRIND, OR SAND VESSEL, OR IT WILL NOT
BE SAFE TO OPERATE. (Note: Any alteration to the vessel
will void the ASME Code Certification and the warranty.)
ANY DAMAGE TO THE VESSEL CAN MAKE IT UNSAFE.
INSPECT OUTSIDE AND INSIDE OF VESSELS REGULARLY
FOR BULGES, CORROSION, DENTS, GOUGES, LEAKS OR
SIGNS OF FIRE. IF DAMAGED, TAKE OUT OF SERVICE
IMMEDIATELY AND NOTIFY YOUR CERTIFYING AUTHORITY.
USE THE PROPER SAFETY RULES FOR THE GAS BEING
PROCESSED.
DO NOT REMOVE THE HATCH COVER UNTIL ALL AIR
PRESSURE IS OUT OF THE VESSEL. PUSH ON THE HATCH
COVER BY HAND TO FIND OUT IF THE VESSEL PRESSURE IS
REDUCED TO ZERO.
DO NOT TRY TO TIGHTEN THE HATCH COVER IF YOU HEAR
OR FEEL A LEAK. IMMEDIATELY SHUT OFF THE AIR OR GAS
SUPPLY TO THE VESSEL AND REDUCE THE DRYER
PRESSURE TO ZERO.
ALWAYS INSTALL A NEW GASKET EVERY TIME THE HATCH
COVER IS REMOVED, OR AT LEAST ONCE PER YEAR.
REPLACE THE HATCH COVER EVERY FIVE YEARS
REGARDLESS OF CONDITION. USE VAN AIR AUTHORIZED
PARTS ONLY.
DO NOT USE POWER TOOLS OR CHEATER BARS TO
TIGHTEN THE NUT ON THE COVER. TOO MUCH FORCE CAN
DISTORT THE COVER AND/OR THE GASKET. IF DAMAGED
BY OVERTIGHTENING, THE COVER CAN BLOW OUT AND
CAUSE SERIOUS INJURY. (Note: Tighten the nut until it is
snug only. When pressure is in the vessel, the seal will be
complete.)
INSPECT THE COVER AND SEALING SURFACE EVERY TIME
THE COVER IS REMOVED, OR AT LEAST ONCE PER YEAR,
FOR DAMAGE SUCH AS CORROSION, CRACKS, OR
DISTORTION. IF THERE IS ANY DAMAGE, INSTALL A NEW
COVER AND GASKET. USE VAN AIR AUTHORIZED PARTS
ONLY.
PAGE 1
Page 2
SECTION 1 INTRODUCTION
1.0 PURPOSE OF OPERATION
The purpose of installing a Van Air single tower dryer in a
compressed air system is to remove the water vapor (humidity)
which has been drawn into the system at the compressor intake.
The Van Air process dries the air as it flows through the vessel,
which is filled with a special drying agent. The dryer operates
automatically. There are no moving parts and no external source of
power is required. If an automatic drain is installed, a power source
is required only to operate the valve.
The wet air enters the centrally located inlet which channels the flow
into the lower portion of the dryer. Liquid water and solid particles
are separated by gravity and fall to the bottom of the vessel.
The process air moves upward through the bed of desiccant tablets
which attract and absorb the moisture from the air before it flows
through the dryer outlet. The tablets dissolve gradually as they
absorb the moisture.
The tablets create a structured bed that does not crush under its
own weight. In the bed of an operating dryer, the lower tablets are
consumed first.
The tablets above the sight windows are virtually unused and serve
as a reserve supply. When the reserve supply is depleted, the dryer
must be refilled to maintain performance.
The solution, which consists of dissolved desiccant and water, falls
into the claim area at the bottom of the vessel. The dryer must be
drained at least once a shift to remove the accumulated solution.
The drain solution may contain libricatants and must be disposed of
properly.
FIGURE 1 DRYER DETAILS
SECTION 2 INSTALLATION
2.1 LOCATION
The ability of a dryer to provide dry compressed air depends on the
correct location of the unit. Inlet air temperature and pressure are
the keys to selecting the proper location.
temperatures remain within a fixed range, locate the dryer in the
coolest indoor area. When air equipment or piping is located in an
air conditioned area, install the dryer in the coolest area--usually the
air conditioned area.
2.1-E AIR RECEIVER
ALWAYS PROCESS AIR THROUGH THE DRYER AT THE
IMPORTANT
LOWEST POSSIBLE TEMPERATURE AND THE HIGHEST PRACTICAL PRESSURE.
2.1-A INLET AIR TEMPERATURE
The dew point of the outlet air is directly related to the inlet air
temperature and the type of desiccant being used. The lower the
inlet temperature, the lower the dew point of the outlet air.
Determine the lowest ambient temperature where the compressed
air is used or where the lines are located. If you are using DRYO-LITE or 10BF desiccants, do not exceed 100oF inlet air temperature. If you are using SP desiccant, do not exceed 80oF inlet air
temperature.
2.1-B AFTERCOOLING
Air discharged by the compressor is extremely hot (from 150oF to
350oF). An aftercooler, finned tubing or extended run of piping will
usually be necessary to reduce the inlet air temperature to the
dryer.
2.1-C OUTDOOR AIR USAGE
If some or all of the air supplied by the Van Air single tower dryer
will be used outdoors, install the dryer outdoors in the coolest
possible area. M ake sure that the dryer is not exposed to ambient
temperatures below the minimum design temperature stamped
on the vessel data tag. When the dryer will be exposed to the
direct rays of the sun, install a sun shield to protect it (i.e. a roof).
2.1-D INDOOR AIR USAGE
If all of the air from the dryer will be used indoors where
PAGE 2
In relation to the air receiver, the Van Air single tower dryer should
be located where it will be provided with the coolest inlet temperature.
If the receiver is located in an area where the ambient temperature
is lower than the outlet air from the aftercooler, locate the dryer
downstream of the receiver to allow additional cooling of the air
before it enters the dryer. (Exception: In systems where usage
creates sudden demands on the air supply, locate dryer before the
receiver to minimize air surges through the dryer.) If the ambient
temperature around the receiver is higher than the outlet air
temperature from the aftercooler, locate the dryer between the
aftercooler and the receiver.
2.1-F SPECIAL EQUIPMENT INSTALLATION
If the Van Air dryer is being installed on a branch line to protect a
specific piece of air-operated equipment, locate the dryer on the high
pressure side of any pressure regulators.
2.1-G OPERATING PRESSURE
More air can be processed through the dryer at higher pressures.
Locate the dryer at the highest practical pressure, but do not exceed
the maximum rated working pressure of the dryer. Refer to the
Maximum Capacities chart on Page 3 for the maximum working
pressure for your dryer.
2.2 PIPING AND ANCILLARY EQUIPMENT
Locate the dryer in the proper location as explained in the previous
section.
If the dryer is being installed in an existing piping system, make sure that
the pipe is free of scale and rust.
Page 3
SECTION 2 INSTALLATION
FIGURE 2 MAXIMUM CAPACITIES -SCFM (Nm3/hr)
MODEL
NO.
D-12
D-16
D-20
D-24
D-30
D-36
MAXIMUM
WORKING
PRESSURE
250 PSIG
250 PSIG
200 PSIG
200 PSIG
200 PSIG
175 PSIG
5 PSIG
0.3 Bar
17
29
27
45
43
73
64
109
107
182
146
248
10 PSIG
0.7 Bar
22
37
33
57
54
91
81
137
135
229
183
311
20 PSIG
1.4 Bar
30
51
47
80
76
128
113
193
189
321
257
437
40 PSIG
2.8 Bar
48
81
74
126
119
203
179
304
298
506
405
689
FIGURE 3 RECOMMENDED INSTALLATION DRAWING
60 PSIG
4.1 Bar
65
111
101
172
163
277
244
415
407
692
554
941
80 PSIG
5.5 Bar
83
140
128
217
206
351
310
526
516
877
702
1192
100 PSIG
6.9 Bar
100
170
155
263
250
425
375
637
625
1062
850
1444
125 PSIG
8.6 Bar
122
207
189
321
304
517
457
776
761
1293
1035
1759
150 PSIG
10.3 Bar
144
244
223
378
359
610
538
915
897
1525
1221
2074
175 PSIG
12.1 Bar
165
281
256
436
414
703
620
1054
1034
1757
1406
2390
200 PSIG
13.8 Bar
187
318
290
493
468
795
702
1193
1170
1988
--
--
250 PSIG
17.2 Bar
231
392
358
608
--
--
--
--
--
--
--
--
NOTE:
ITEMS CALLED OUT IN THIS DRAWING
ARE NOT SUPPLIED WITH THE DRYER.
REFERENCE FIGURES 1 & 4 FOR ITEMS
INCLUDED WITH DRYER.
PAGE 3
Page 4
SECTION 2 INSTALLATION
FIGURE 4 DRYER DIMENSIONAL DETAILS
MODEL
NO.
D-12
D-16
D-20
D-24
D-30
D-36
PAGE 4
APPROX
WEIGHT
w/o Desiccant
130 LBS
145 LBS
210 LBS
285 LBS
640 LBS
780 LBS
A
2" NPT
2" NPT
2" NPT
2" NPT
3" NPT
3" 150#
FLANGE
B
13-7/8"
352.4mm
15-1/2"
393.7mm
15-3/4"
400.1mm
17"
431.8mm
21-7/8"
555.6mm
24-5/8"
65.5mm
C
38-1/4"
971.6mm
41-3/4"
1060.5mm
42-5/8"
1082.7mm
44"
1117.6mm
44-7/8"
1139.8mm
48-5/8"
1235.1mm
D
18"
457.2mm
19-1/2"
495.3mm
23-1/2"
596.9mm
26"
660.4mm
32"
812.8mm
44-5/8"
1133.5mm
E
12-3/4"
323.9mm
16"
406.4mm
20"
508mm
24"
609.6mm
30"
762mm
36-5/8"
930.3mm
F
51"
1295mm
54-5/8"
1387.5mm
55-7/8"
1419.2mm
58-3/4"
1492.3mm
63-1/2"
1612.9mm
69-3/8"
1762.1mm
G
8-5/8"
219.1mm
12-3/4"
323.9mm
16"
406.4mm
16"
406.4mm
24"
609.6mm
24"
609.6mm
H
3-7/8"
98.4mm
3-1/2"
88.9mm
3-3/8"
85.7mm
3-3/4"
95.3mm
4-3/8"
111.1mm
5"
127mm
J
NA
NA
NA
NA
NA
NA
17"
431.8mm
19-5/8"
498.5mm
21-5/8"
549.3mm
Page 5
SECTION 2 INSTALLATION
2.2-A INLET AND BYPASS PIPING
Using Figure 3 as a reference, make the necessary piping
connections into the dryer.
Inlet and outlet isolation valves should be installed on the dryer.
These valves will aid in the start up and shutdown of the dryer. A
bypass valve and piping should also be installed. This will allow
the dryer to be taken off stream without interrupting the air system.
2.2-B OPTIONAL PRESSURE RELIEF VALVE
A pressure relief valve should be installed to conform to OSHA
safety standards. Refer to OSHA Standard Section 1910.169,
paragraph b, subparagraph 3 and any other federal, state or
local codes concerning pressure vessels.
A coupling was provided on the upper back side of the vessel for
installing the relief valve. A bushing will be necessary to reduce
the coupling to the valve inlet size. Reference FIGURE 3 for
location.
Listed below are the recommended relief valves available for
each dryer. Contact your local Van Air representative to order.
DRYER
CONN. SIZE
1" NPT
1" NPT
2" NPT
2" NPT
2" NPT
3" NPT
VALVE SIZE
1/2" NPT
1/2" NPT
3/4" NPT
3/4" NPT
1" NPT
1-1/4" NPT
DRYER
D-12
D-16
D-20
D-24
D-30
D-36
VALVE
PART NO.
14-1462
14-1462
14-1810
14-1800
14-2204
14-2203
2.2-C OPTIONAL GAUGE INSTALLATION
A coupling was provided on this dryer for the installation of a
gauge.
Three gauges are available for this dryer from your Van Air
representative.
Thread the gauge kit into the coupling provided on the lower, front
side of the vessel as shown in FIGURE 3.
GAUGE KITS
PRESSURE
TEMPERATURE
COMBINATION PRESSURE/TEMPERATURE
NOTE: For dryer models D-12 through D-20 only, the gauge
coupling can be used for the installation of a high level alarm
instead of a gauge.
PART NO.
29-0252
29-0326
29-0200
2.2-D MANUAL DRAIN VALVE
A 1" NPT brass ball valve was shipped separately with the dryer.
Install the valve on the drain line. Reference FIGURES 3 & 4 for
location.
IMPORTANT
The drain solution may contain lubricants. Comply with all
applicaple regulations concerning the disposal of these
chemicals.
The drain line of the dryer can be remotely piped . DO NOT connect
the drain line to a pressurized line. Make sure that the line is vented
to atmospheric pressure. Any remote drain piping should be of the
same size and on the same level or lower than the drain valve.
When installing the drain line, make sure that the discharge end of the
line or valve is directed away from people and equipment.
2.2-E OPTIONAL AUTOMATIC DRAIN VALVE
The MDV-400I drain valve is recommended, other materials,sizes,
and voltages are available . Contact your local VAN AIR representative
to order.
MODEL VOLT SIZE MATERIAL PART NO.
MDV-400I 115 1" NPT BRASS 39-2411121
Complete the automatic drain valve installation as shown in
FIGURE 2 and outlined in the instructions supplied with the drain.
The drain line can be remotely piped, follow the precautions as
outlined in Section 2.2-D.
2.2-F AFTERFILTER
The installation of an afterfilter prevents any accidental flow of
materials from the dryer into the downstream piping.
The afterfilter may be installed before or after the outlet isolation
valve. If the afterfilter is installed before the isolation valve, the filter
can be isolated from the air system when the dryer is isolated for
maintenance.
Below is a chart of VAN AIR recommended filters. Contact your local
VAN AIR representative to order.
DRYER
D-12
D-16
D-20
D-24
D-30
D-36
FILTER
F200-100-1-B
F200-150-1-B
F200-265-1-1/4-B
F200-400-2-B
F200-600-3-B
F200-800-3-B
DEL-P GAUGE
PD-5
PD-5
PD-5
PD-5
PD-5
PD-5
2.2-G DESICCANT INSTALLATION
IMPORTANT
This dryer was shipped WITHOUT the desiccant installed.
The desiccant MUST BE INSTALLED before using the dryer
THE USE OF CHEMICALS OTHER THAN VAN AIR DESICCANT
WILL VOID THE WARRANTY ON THE DRYER.
CAUTION
DO NOT CONNECT THE DRAIN TO A PRESSURIZED LINE.
DO NOT INSTALL THE DRAIN LINE IN THE DIRECTION OF
PEOPLE AND EQUIPMENT. WHEN THE DRYER IS DRAINED
THE DRAIN SOLUTION WILL BE DISCHARGED UNDER
LINE PRESSURE. POINTING THE DRAIN IN THE DIRECTION
OF PEOPLE AND EQUIPMENT MAY RESULT IN INJURY
AND DAMAGE.
DO NOT INSTALL A FLOAT TYPE OR SOLENOID TYPE
DRAIN ON THE DRYER. THE DRAIN SOLUTION WILL
CAUSE THESE TYPES OF DRAINS TO FAIL, THUS
RESULTING IN FLOODING OF THE DRYER.
The procedures for filling the dryer with desiccant are outlined in
Section 4.4 of this manual.
2.2-H HIGH LEVEL ALARM HLA-120 (P/N 26-3667)
The HLA120 high level alarm is designed to alert personnel that the
drain solution in the dryer has reached an unacceptable level. A
coupling is provided on the dryer models D-24 through D-36. For
dryer models D-10 through D-20 the gauge coupling can be used
to install the alarm instead of a gauge. Contact your local VAN AIR
representative to order.
Install the HLA120 high level alarm in the coupling as shown in
FIGURE 3 and as outlined in the instructions supplied with the
alarm.
PAGE 5
Page 6
SECTION 3 OPERATION
3.1 START UP PROCEDURES
Close the inlet and outlet isolation valves. Open the bypass
valve and manual drain valve.
Open the outlet isolation valve SLOWLY and allow some air to bleed
through the manual drain valve; then close the manual drain valve.
When the dryer reaches normal operating pressure, SLOWLY turn
the inlet valve to full open position; then close the bypass valve.
If the vessel was installed without the bypass or isolation valves,
SLOWLY pressurize the air system. Allow some air to bleed through
the manual drain valve. Once the vessel starts to pressurize, the
manual drain valve can be closed. Close the bypass valve. The dryer
is now on stream.
CAUTION
Make sure that the dryer is not subjected to sudden flow
surges. Always open the valves slowly to permit gradual
equalization of pressure between the dryer and the air
supply lines.
On a new installation, continue to drain all downstream traps for
several days (or until no water is evident) after dryer is installed.
This period is required to dry out any accumulated water in the
compressed air system. Once the water is removed, the downstream traps should not need to be drained again.
3.2-B REFILLING THE DRYER WITH DESICCANT
During the VAN AIR drying process, the desiccant tablets dissolve
slowly. More tablets must be added to the supply when the top of
the bed drops to the sight window level (minimum level). Reference
FIGURE 5.
The desiccant consumption rate is dependent on several factors,
such as inlet temperature, flow, pressure and the type of desiccant
being used . With average conditions, the desiccant will usually
need to be added only two to three times per year when the dryer
is operating one shift per day. However, until the actual usage rate
is determined, check the bed level monthly.
3.2 OPERATING THE DRYER
The simple design of the single tower dryer allows for easy
operation. The dryer requires two procedures to ensure peak
performance.
3.2-A DAILY DRAINING
The accumulated solution in the bottom of the dryer should be
drained at least once every 4 to 8 hours of operation.
Depending on actual operating conditions, the dryer may
require draining on a more frequent basis.
If an automatic ball valve type drain valve was installed on the
dryer, set the time cycle for every 4 to 8 hours. If a manual
drain valve was installed, it must be opened at least once every
4 to 8 hours to drain the dryer.
CAUTION
If the dryer is not drained regularly, it may become
flooded. Accumulated liquid may enter the air system and
cause damage to downstream equipment.
Reference Section 4.4-B for estimated consumption rates and
refilling instructions.
IMPORTANT
Use VAN AIR desiccant only. Filling dryer with any
other material will void the warranty.
3.3 USING THE SIGHT WINDOWS
WARNING
IF THE SIGHT WINDOWS ARE DAMAGED IN ANY WAY,
THEY MUST BE REPLACED IMMEDIATELY WITH VAN AIR
PART NO. 26-0104 only. REFERENCE SECTION 4.3.
To check the level of the desiccant bed, look into one of the sight
windows. When the top of the desiccant bed is level with the sight
windows, the desiccant supply has dropped to the minimum level.
The bed must be replenished to raise the bed level to the maximum
level.
SECTION 4 MAINTENANCE
4.1 DAILY PROCEDURES
If an automatic drain valve was not installed on the dryer, the
accumulated drain solution from the bottom of dryer must be drained
after every 4 to 8 hours of operation . Open manual drain valve and
allow the solution to discharge from the dryer; then close the manual
drain valve securely.
4.2 MONTHLY PROCEDURES
Check the level of the desiccant bed by looking into the sight window.
If the top of the desiccant bed is level with the sight window, the
desiccant bed must be replenished.
Check the operation of all equipment installed before and after the
dryer.
4.3 REPLACING THE SIGHT WINDOWS
(P/N 26-0104)
WARNING
DEPRESSURIZE DRYER COMPLETELY BEFORE
REMOVING THE SIGHT WINDOW.
Using a pipe wrench, unthread the old sight window. Remove all
pipe sealant, rust or dirt from the coupling.
Apply a layer of pipe sealant to the threads of the new sight
window. DO NOT USE TEFLON TAPE. Tape may prevent the
sight window from threading into the coupling far enough.
Check the afterfilter element condition. If the pressure differential
across the filter is high (6 to 9 PSID), replace the element.
Inspect the hatch cover for signs of corrosion and/or leaks. Replace
the cover and/or gasket if necessary.
PAGE 6
Page 7
SECTION 4 MAINTENANCE
4.4 ADDITION OF DESICCANT
WARNING
DO NOT REMOVE, REPAIR, OR REPLACE ANY ITEM ON
THE DRYER WHILE IT IS UNDER PRESSURE.
DEPRESSURIZE THE DRYER COMPLETELY BEFORE
STARTING INSTALLATION AND/OR MAINTENANCE
PROCEDURES. SERIOUS PERSONAL INJURY MAY
RESULT IF THESE SAFETY RULES ARE NOT FOLLOWED.
DO NOT REMOVE THE HATCH COVER UNTIL ALL AIR
PRESSURE IS OUT OF THE VESSEL. PUSH ON THE
HATCH COVER BY HAND TO FIND OUT IF THE VESSEL
PRESSURE IS REDUCED TO ZERO.
DO NOT TRY TO TIGHTEN THE HATCH COVER IF YOU
HEAR OR FEEL A LEAK. IMMEDIATELY SHUT OFF THE
AIR OR GAS SUPPLY TO THE VESSEL AND REDUCE
THE DRYER PRESSURE TO ZERO.
ALWAYS INSTALL A NEW GASKET EVERY TIME THE
HATCH COVER IS REMOVED, OR AT LEAST ONCE PER
YEAR. REPLACE THE HATCH COVER EVERY FIVE
YEARS REGARDLESS OF CONDITION. USE VAN AIR
AUTHORIZED PARTS ONLY.
DO NOT USE POWER TOOLS OR CHEATER BARS TO
TIGHTEN THE NUT ON THE COVER. TOO MUCH FORCE
CAN DISTORT THE COVER AND/OR THE GASKET. IF
DAMAGED BY OVERTIGHTENING, THE COVER CAN
BLOW OUT AND CAUSE SERIOUS INJURY. (Note:
Tighten the nutonly until it is snug . When pressure is in
the vessel, the seal will be complete.)
INSPECT THE COVER AND SEALING SURFACE EVERY
TIME THE COVER IS REMOVED, OR AT LEAST ONCE
PER YEAR, FOR DAMAGE SUCH AS CORROSION,
CRACKS, OR DISTORTION. IF THERE IS ANY DAMAGE,
INSTALL A NEW COVER AND GASKET. USE VAN AIR
AUTHORIZED PARTS ONLY.
Open the bypass valve. Close the dryer inlet and outlet isolation
valves. If the bypass and inlet and outlet isolation valves were not
installed, shut down the air system.
Open the drain valve and allow the dryer to depressurize completely.
Loosen the nut on the hatch cover.
Push on the hatch cover. If the vessel is depressurized, the cover will
unseal. Once the seal is broken, tilt the hatch cover and remove it
from the dryer.
Add the amount of desiccant tablets required to raise the supply to
the maximum operating level or to maximum level (see FIGURE 5);
then level off the tablet bed.
CAUTION
Make sure that the desiccant does not cover the screen
on the outlet pipe.
Do NOT overfill the vessel. Adequate space must be left
to allow the hatch cover to be installed.
Check the condition of the hatch cover. If it is damaged, it must be
replaced. The gasket should be replaced every time the hatch cover
is removed or at least once a year.
Check the sealing surface of the opening. If it is contaminated with
dirt or rust, it must be cleaned before installing the hatch cover. A
contaminated surface may prevent the gasket from properly sealing.
Install the filler hatch cover and gasket. Finger tighten the nut on the
hatch cover. Overtightening will cause damage to the nut. The cover
will seal when the vessel is pressurized.
Start up the dryer following the procedures in Section 3.1.
4.4-A BED LEVEL GUIDE
To determine the supply of desiccant in the dryer, insert a
measuring stick through the filler hatch until it reaches the top of
the desiccant bed; dimensions in FIGURE 5 are calculated from
the filler hatch to levels indicated on the drawing. (NOTE:
Dimensions are approximate and are intended as a general guide
only.)
4.4-B DESICCANT USAGE GUIDE
The chemical and physical characteristics of Van Air desiccant
contribute to its effectiveness and economy.
The DESICCANT CONSUMPTION RATE should be used as a
guide to estimate the usage of desiccant your installation will require.
The formula is based on an annual usage rate of one shift per day,
5 days per week and 50 weeks per year or 2,000 operating hours per
year. The figure is an average and may vary depending upon your
actual conditions (i.e. 24 hour operation, higher inlet temperature,
excessive liquid water content and/or contaminants.)
DESICCANT CONSUMPTION
(Based on 1 shift for a one year period @ 100 psig inlet pressure and
75oF inlet temperature, 100% RH.)
FLOW
SCFM
20
50
100
200
300
500
700
1000
To use the chart, first determine the SCFM that is being
processed through the dryer. Locate the nearest flow rate listed
on the chart and interpolate as necessary.
The consumption rate is proportional to the moisture loading.
Each 20oF increase in inlet temperature changes the moisture
loading by a factor of nearly 2:1.
The quantity shown in the consumption rate chart is NOT the
quantity that must be added to the dryer at one time. The bed
level should be maintained at least to the minimum level at all
times to ensure optimum drying capabilities. The consumption
rate is an approximation of how much desiccant will be
added over a period of one year.
DRY-O-LITE
LBS/YEAR
26.4
66.0
132.0
264.0
396.0
660.0
924.0
1320.0
SP
LBS/YEAR
133
332.5
665.0
1330.0
1995.0
3325.0
4655.0
6650.0
10 BF
LBS/YEAR
115.2
288.0
576.0
1152.0
1728.0
2880.0
4032.0
5760.0
PAGE 7
Page 8
SECTION 4 MAINTENANCE
FIGURE 5 BED LEVEL DETAIL
BED DIMENSIONS
INCHES (centimeters)
MODEL
D-12
D-16
D-20
D-24
D-30
D-36
A
MAX.
Level
4.56
11.59
5.29
13.34
6.38
16.19
7.38
18.73
9.63
24.45
11.31
28.73
B
MIN.
Level
17.63
44.77
16.88
42.86
16.38
41.59
16.94
43.02
14.13
35.88
17.31
43.97
C
Total
Depth
30.38
77.15
31.19
79.22
33.13
84.14
33.75
85.73
31.88
80.96
35.06
89.06
DRY-O-LITE QUANTITY*
POUNDS (kilograms)
FILL
Lbs./In
MODEL
D-12
of bed**
5.22
2.37
D-16
8.19
3.71
D-20
12.96
5.88
D-24
18.43
8.36
D-30
29.67
13.46
D-36
44.49
20.18
* Amounts are pounds (kilograms) required to fill dryer to levels indicated.
** Amounts in italics are kilograms per centimeter of bed depth.
PAGE 8
MIN.
Level
66.56
30.19
117.22
53.17
217.12
98.48
309.80
140.52
526.56
238.84
789.63
358.17
FILL
MAX
Level
134.74
61.12
212.42
96.35
346.73
157.27
486.01
220.45
660.06
299.40
1056.54
479.24
MIN to
MAX
Level
68.19
30.93
95.21
43.18
129.62
58.79
176.21
79.93
133.49
60.55
266.92
121.07
SP or HPD QUANTITY*
POUNDS (kilograms)
FILL
Lbs./In
of bed**
3.83
1.74
6.01
2.72
9.51
4.31
13.51
6.13
21.76
9.87
32.62
14.80
MIN.
Level
48.81
22.14
85.96
38.99
159.22
72.22
227.19
103.05
386.15
175.15
579.06
262.66
FILL
MAX
Level
98.82
44.82
115.78
52.52
254.27
115.33
356.41
161.66
484.04
219.56
774.80
351.44
MIN to
MAX
Level
50.00
22.68
69.82
31.67
95.06
43.12
129.22
58.61
97.90
44.41
195.74
88.79
10 BF QUANTITY*
POUNDS (kilograms)
FILL
Lbs./In
of bed**
4.52
2.05
7.10
3.22
11.23
5.10
15.97
7.24
25.71
11.66
38.56
17.49
MIN.
Level
57.68
26.16
101.59
46.08
188.17
85.35
268.50
121.79
456.35
207.00
684.34
310.41
FILL
MAX
Level
116.78
52.97
184.10
83.51
300.57
136.34
421.21
191.06
572.05
259.48
915.67
415.34
MIN to
MAX
Level
59.09
26.80
82.51
37.43
112.34
50.96
152.71
69.27
115.70
52.48
231.33
104.93
Page 9
SECTION 5 TROUBLESHOOTING
1. DECREASED PERFORMANCE - High desiccant usage.
High inlet air temperatures.
Check the aftercooler performance. Make sure that the
aftercooler was properly sized and installed. Check the aftercooler
operation manual for further details.
If an aftercooler was not installed, one may be required.
Check the compressor capacity or air usage vs. the dryer rating.
3. DECREASED PERFORMANCE - low desiccant usage.
The desiccant bed may be contaminated.
The dryer will tolerate normal amounts of compressor lubricant. If
the compressor manufacturer's recommended lubrication rate is
exceeded, the desiccant bed can become contaminated with
compressor lubricants.
Periodically check the desiccant bed. If the tablets are discolored
(deep yellow or brown), the bed may be contaminated.
Was a different compressor installed?
High ambient temperatures.
Check the location of the dryer for changes in ambient temperatures.
Was the dryer moved to a different location?
Was a piece of equipment or piping installed near the dryer that
caused an increase in ambient temperatures? Relocate the dryer
or equipment if possible. If relocation is not possible, correct the
ambient temperature.
Dryer overloaded.
Check the flow through the dryer. Check the flow at peak usage
periods. Have the flow requirements of the system increased?
Was the dryer properly sized for the actual operating conditions?
Check the capacity of the dryer for the system conditions. If the
system requirements exceed the dryer's capability, a larger dryer
must be installed.
Desiccant bed below required level.
Check the desiccant bed level. The level should be checked at
least once a month. The usage of desiccant will vary with the
operating conditions and the type of desicccant being used. The
dryer will require more desiccant during the warmer months of the
year.
Desiccant quantities and filling procedures are outlined in Section
4.4 of this manual.
If the bed has become contaminated, it can be flushed with an
adequate supply of water. Depending upon the severity of
contamination, it might be necessary to completely flush the entire
bed from the dryer and replace it with new desiccant.
Check the compressor for proper operation. The compressor
might be worn or over lubricated. Check the compressor
operator's manual and correct.
Check the atmospheric air near the compressor air intake. Heavy
concentrations of acid fumes or smoke and dust will cause
contamination if they are drawn into the air system. Check or
install a filter on the compressor intake.
If it is not possible to reduce the amount of lubricants in the air
system, a separator and/or coalescing filter should be installed
before the dryer.
2. LIQUID DOWNSTREAM OF THE DRYER.
Improper draining. The dryer may be flooded.
The dryer must be drained at least once for every 8 hours of
operation.
Check the drain valve(s) and piping for clogs. Repair or replace
faulty valves. If the piping is clogged, it must be cleared.
If the dryer is installed outdoors where ambient temperatures fall
below freezing, the drain line and valve(s) may freeze. If ambient
temperatures fall below freezing, the drain line can be wrapped
with heat tracing and/or insulation to prevent freezing.
If maintaining the required draining schedule is a problem, an
automatic ball type drain valve should be installed. Reference
Section 2.2-F in this manual for installation instructions.
IMPORTANT: Never install a float type or solenoid type drain valve
on this dryer.
Bypass valve open or faulty.
Check the dryer bypass valve. It might be faulty or open allowing
untreated air to enter the air system.
Low or no desiccant in the dryer.
Check the dryer deissiccant bed level. Reference Section 4.4 for
filling quantities and procedures.
If the above check list does not remedy the problem, consult your local VAN AIR distributor or call
the VAN AIR factory in Lake City, Pennsylvania PHONE (814) 774-2631 or FAX (814) 774-
3482.
PAGE 9
Page 10
SECTION 6 REPLACEMENT PARTS
ITEM
1
Gasket for 3" x 4" hatch cover
DESCRIPTION
Gasket for 4" x 6" hatch cover
2
Hatch Cover, 3" x 4"
Hatch Cover, 4" x 6"
3
Sight Window
4
Manual Drain Valve 1" NPT
5
DESICCANT
DRY-O-LITE Desiccant, 50 LB BAG
DRY-O-LITE Desiccant, 506 LB DRUM
SP Desiccant, 50 LB BAG
10BF Desiccant, 25 LB PAIL
6
OPTIONAL PRESSURE RELIEF VALVES
1/2" NPT 250# set pressure
3/4" NPT 200# set pressure
3/4" NPT 200# set pressure
1" NPT 200# set pressure
1-1/4" NPT 175# set pressure
PART NO.
18-0391
18-0394
46-3002
46-3003
26-0104
14-0451
33-0311
33-0203
33-0205
33-0232
14-1462
14-1810
14-1800
14-2204
14-2203
D12
QTY
1
-1
-2
1
3
-4
5
1
--
--
--
--
D16
QTY
1
-1
-2
1
4
-4
8
1
--
--
--
--
D20
QTY
-1
-1
2
1
7
-6
12
-1
--
--
--
D24
QTY
-1
-1
2
1
10
-8
17
--
-1
--
--
D30
QTY
-1
-1
2
1
13
-10
23
--
--
--
1
--
D36
QTY
-1
-1
2
1
22
--
16
37
--
--
--
-1
7
OPTIONAL GAUGE KITS
Pressure gauge kit
Pressure gauge only
Temperature gauge kit
Temperature gauge only
Thermowell only
Combination pressure/temperature gauge
8
OPTIONAL HIGH LEVEL ALRM
HLA-120 High level alarm kit
OPTIONAL AUTOMATIC DRAIN VALVE
9
MDV-400I 1" NPT 115Volt Brass
10
White touch up paint (9 oz. spray can)
29-0252
29-0151
29-0326
29-0108
29-0107
29-0200
26-3667
39-2411121
45-0152
1
1
1
1
1
1
--
1
1
1
1
1
1
1
1
--
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
PAGE 10
Page 11
SECTION 6 REPLACEMENT PARTS
PAGE 11
Page 12
YOUR VAN AIR REPRESENTATIVE IS:
NAME:
COMPANY:
ADDRESS:
CITY: STATE: ZIP:
PHONE: FAX:
ATTACH BUSINESS CARD HERE
MAKING COMPRESSED AIR AND GAS WORK BETTER SINCE 1944.
PAGE 12
2950 Mechanic Street
Lake City, PA 16423-2095
Phone: 814/774-2631
Fax: 814/774-3482
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