Refrigerating Specialties Division
1
BULLETIN DN23-11
Type A4AM-DN
Februay 2002
Installation and Service Information
Electrically Compensated
Pressure Regulators
Type A4AM-DN, A4AOM-DN, & A2BM-DN
PORT SIZE 3/8”-4” (20-100MM)
FOR AMMONIA, R22, R134A, R502
OTHER COMMON REFRIGERANTS
FEATURES
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Unique modular construction
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Suitable for all common refrigerants and oils
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Easy to service
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Interchangeable parts
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362 psig (25 bar) design pressure (PS)
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Pilot operated characterized Modulating Plug for precise
control
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Manual opening stem
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Close coupled strainers, optional
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Stainless steel diaphragm
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Flanges for threaded or welded steel pipe and copper tube
(copper not for ammonia)
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Available in most standard R/S regulator variations
(A4AMS, A4ADM, etc...)
•
Complies with Pressure Equipment Directive 97/23/EC
Fig. 1 A4AM
Description:
These heavy duty, pilot operated pressure regulators are
suitable for R-717, R-22, R-502 and other common refriger-
ants and fluids approved for use in refrigeration systems. All A4
Regulators are pilot operated using upstream pressure for the
opening force and require a minimum 2 psi (0.14 bar) pressure
drop to fully open. These valves are generally ordered with a
close coupled upstream strainer to prevent the entrance of
foreign material into the valve and the rest of the system. The
fluid temperature range for the A4 Series of Regulators is -50F
to 220F (-45C to 105C).
PURPOSE:
These electrically compensated A4AM inlet pressure regula-
tors modulate the flow of refrigerant gas or liquid to maintain a
varying upstream (or inlet) pressure in response to an electrical
signal applied to a low voltage motor mounted on a regulator
pilot. When supplied with Range D, they also can be used to
control condensing pressures; for example, as part of a heat
reclaim system.
These regulators are excellent in controlling evaporator pres-
sure/temperature where load fluctuations are great, such as
hot carcass chilling, warm fruit and wine chilling and cooling
tunnels. They are also useful where product load is fairly
constant but very close temperature or humidity control is
desired.
When the regulator is used in a location where excessive
moisture, corrosion or explosive atmosphere exists, or in low
temperature applications where ice could accumulate on the
pilot valve stem, the A4AR with A2BM remote pilot can be used.
(See Fig. 7)
I S O 9 0 0 1 C E R T I F I E D
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