Parker A4AT-DN Installation And Service Information

TEMPERATURE COMPENSATED
PRESSURE REGULATORS
TYPE A4AT-DN, A4AOT-DN
Port Size 3/4" - 4" (20 - 100 mm)
For Ammonia, R22, R134a, R404a R507
Other Refrigerants and Oils

FEATURES

• Pilot operated characterized Modulating Plug
for precise control
• Suitable for all common refrigerants and
mineral oil
• 362 psig (25 bar) design pressure (PS)
• Flanges for threaded or welded steel pipe
and copper tube (copper not for ammonia)
• Unique Modular construction
• Interchangeable parts
• Close coupled strainers, optional
• Many control variations are possible with
the use of a few modules and kits
• Stainless Steel Diaphragm
• Manual Opening Stem
• Complies with Pressure Equipment Directive
97/23/EC
Refrigerating Specialties Division
310217
Fig. 1
BULLETIN DN23-09
A4AT-DN
February 2002
Installation and Service Information
Description:
These compact, heavy duty, pilot operated regula-
tors are suitable for Ammonia, R22, R134a, R404a,
R707 and other common refrigerants and fluids
approved for use in refrigeration systems.
Standard Temperature Range is -20
30 o C to +30 o C). Also available: 60
to 60 o C). Maximum temperature to which thermal
bulb can be exposed is 105
These valves are generally ordered with close
coupled upstream strainer to prevent entrance of
foreign material into the valve and the rest of the
system.

PURPOSE

The temperature compensated pressure regulator
differs from the conventional pressure regulator in
that rather than maintaining a previously set con-
stant pressure, this regulator modulates pressure in
accordance with the demands of the load. The
1
I S O 9 0 0 1 C E R T I F I E D
A4AOT-DN
o F to 80 o F (-
o F to 140 o F (20
o o
F (65 C).
o C