Van Air Systems D8 User Manual

JANUARY 2005

P/N 32-0271 rev C

INSTALLATION, OPERATION, & MAINTENANCE INSTRUCTIONS

FOR

SINGLE TOWER

COMPRESSED AIR DRYER

MODELS

D-4 & D-8

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 FILL PORT UNTIL ALL AIR PRESSURE IS OUT OF THE VESSEL.

PAGE 1

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 in the top portion 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.

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.

area. Make 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).

ALWAYS PROCESS AIR THROUGH THE DRYER AT THE
LOWEST POSSIBLE TEMPERATURE AND THE HIGHEST
PRACTICAL PRESSURE.

IMPORTANT

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 DRY-O-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

FIGURE 2 MAXIMUM CAPACITIES -SCFM (Nm3/hr)

MAXIMUM

3

4.8

15

24.1

40 PSIG

2.8 Bar

4.8

7.7

24

38.6

MODEL

NO.

D 4

D 8

WORKING

PRESSURE

250 PSIG

250 PSIG

5 PSIG

0.3 Bar

1.7

2.7

9

14.5

10 PSIG

0.7 Bar

2.2

3.5

11

17.7

20 PSIG

1.4 Bar

60 PSIG

4.1 Bar

6.5

10.5

33

53

2.1-D INDOOR AIR USAGE

If all of the air from the dryer will be used indoors where 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

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.

80 PSIG

5.5 Bar

8.3

13.3

41

66

90 PSIG

6.2 Bar

9.1

14.6

46

74

100 PSIG

6.9 Bar

10

16

50

80

125 PSIG

8.6 Bar

12.2

19.6

61

98

150 PSIG

10.3 Bar

14.4

23.2

200 PSIG

13.8 Bar

18.7

30.1

72

116

94

151

250 PSIG

17.2 Bar

23.1

37.1

115

185

PAGE 2

SECTION 2 INSTALLATION

FIGURE 3 RECOMMENDED INSTALLATION DRAWING

NOTE:
ITEMS CALLED OUT IN THIS DRAWING
ARE NOT SUPPLIED WITH THE DRYER.
REFERENCE FIGURES 1 & 4 FOR ITEMS
INCLUDED WITH DRYER.

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 FIGURE
2 located on page 3 for the maximum working pressure for your dryer.

2.2-D MANUAL DRAIN VALVE

The drain port is a 1/2" NPT tapped hole in the
center of the vessel bottom head.

Shipped separately with the dryer is (1) 1/2" NPT
close nipple and (1) 1/2" NPT brass ball valve.
Install the nipple and valve into the drain port.

The drain of the dryer can be remotely piped away
from the dryer. 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.

IMPORTANT
The drain solution may contain lubricants.
Comply with all applicable regulations
concerning the disposal of these chemicals

CAUTION

DO NOT CONNECT THE DRAIN TO A

PRESSURIZED LINE.

CAUTION

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.

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.

The dryer will be supported by the piping system. Adequate pipe
supports must be used to prevent damage to the pipeline and dryer.

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. The
inlet isolation valve should be mounted before the pressure relief
valve. The outlet isolation valve should be installed on the dryer outlet.

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 (p/n 14-2213)

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.

2.2-C OPTIONAL PRESSURE GAUGE (p/n 29-0150)

An optional pressure gauge is available for this dryer.

DO NOT INSTALL A FLOAT TYPE (OTHER THAN THE PDV-500)
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.

2.2-E OPTIONAL AUTOMATIC DRAIN VALVE (p/n 39-2211121)

The MDV-400I drain valve is recommended. Use model PDV-500 (PN
39-0283) for pneumatic applications. Contact your local VAN AIR
representative to order.

Complete the automatic drain valve installation as outlined in the
instructions supplied with the drain. The drain line can be remotely
piped, follow the precautions as outlined previously.

2.2-F AFTERFILTER

The installation of an afterfilter prevents any accidental flow of materials
from the dryer into the downstream piping.

The afterfilter can 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.
Contact your local VAN AIR representative to order.

DRYER FILTER

D-4 F200-15-1/4-B

D-8 F200-55-1/2-B

2.2-G DESICCANT INSTALLATION

IMPORTANT
This dryer was shipped WITHOUT the desiccant installed. The
desiccant MUST BE INSTALLED before using the dryer

The procedures for filling the dryer with desiccant are outlined in Section

4.4 of this manual.

PAGE 3