Arrow F-20 User Manual

Owner’s Manual
Refrigerated
Compressed Air Dryers
Model F-20

Read carefully before attempting to assemble, install, operate or maintain the
product described. Protect yourself and others by observing all safety information.
Failure to comply with instructions could result in personal injury and/or property
damage. Retain instructions for future reference.

WARNING: Air treated by this equipment is not suitable for breathing without
further purifi cation. Refer to O.S.H.A. standards for the requirements for breathing
quality air.

Figure 1 - F-20

ARROW DRYERS 745 CLARK AVE. BRISTOL, CT 06010 TOLL FREE: [phone]

Form F-0031A
Revised 10/04

1) Separator

2) Compressor

3) Expansion/Control Valve

4) Refrigerant Filter

5) Fan Motor

6) Power On Light/Switch

7) Dew Point Indicator

8) Power Cord

9) Drain Line

1

Receiving and inspection

Arrow Dryers are carefully prepared for shipment at the
factory to protect them from damage in transit. Dryers
are shipped F.O.B. factory. Immediately upon arrival,
check the dryer for possible damage. If

damage is found, report it to the carrier and file
a damage claim.

Check the suction pressure gauge. If the suction pressure
gauge reads zero, it indicates a possible refrigerant leak.
Notify your dealer immediately.

Be sure you have the right dryer. Check the nameplate for
voltage and amperage

Location and Installation

Locate the dryer indoors in a protected area where ambi­ent temperature will range between 45ºF and 100ºF. Dryers
are usually located near the compressor. Do not cycle the
dryer with the compressor. If an aftercooler is used after the
compressor, install the dryer downstream of the aftercooler
and receiver (see figure 2). Install the dryer so that there is
sufficient room around it to permit circulation of air through
the refrigeration condensing unit. Allow for easy access into
the dryer through the cover panel.

Check the nameplate for voltage and amperage. The dryer
is furnished with a 6 foot electrical cord for connection to a
grounded outlet.

How the Air Dryer Works

Compressed air enters the inlet and passes through the
air-to-air heat exchanger where the air is partially cooled
by the exiting cold air. Next, the air passes through a re­frigerant-to-air heat exchanger where it is cooled to near
the freezing point of water. As the air is cooled, it loses the
capacity to hold water vapor. The water vapor condenses
into water droplets and drains to the separator. Passing
through the separator, air flow slows down and causes
more water to condense and collect in the bottom of the
separator bowl. The water is exhausted by the float drain
(see figure 4).

The compressed air, now at a pressure dew point of 35ºF,
leaves the dryer through the air-to-air heat exchanger
where it is heated by the incoming air.

Typical Compressed Air Systems

The dryer can be mounted on a wall with the key hole slots
provided or on a floor stand.

Be sure that the compressor air passes through the dryer
in the proper direction. Connect the compressed air lines to
the inlet and outlet connection as marked on the cabinet.
Connect the air lines with standard pipe fittings.

The mechanical separator has an automatic float drain with
a ⅜” plastic drain line connection that exits through the
dryer cabinet.

It is recommended that a bypass line is piped around the
dryer. Shutoff valves should be installed at both inlet and
outlet, with another valve in the bypass line. This complies
with O.S.H.A. lockout regulations and permits the dryer to
be removed from the system or serviced without turning off
the air supply.

3 Valve Dryer By-Pass

Air Receiver

Compressor

Figure 2

Aftercooler

Air Flow

Separator w/ Auto Drain

2

Air Dryer

Condensate

Drain