Refrigerating Specialties Division
1
BULLETIN 23-07B
Type A4AO, A4AOE, A4AOS, A4AOSE
August 2006
Installation, Service and Parts Information
ADAPTOMODE
®
OUTLET
PRESSURE REGULATORS
Types: A4AO, A4AOE, A4AOS and
A4AOSE
Port Size 20 - 100 mm (3/4” - 4”)
FOR AMMONIA, R-12, R-22, R-502
OTHER REFRIGERANTS AND OIL
FEATURES
• Pilot operated characterized Modulating Plug
precise control
• Suitable for all common refrigerants and oil
• 27.6 bar (400 psig) design pressure (MRP)
• Flanges for threaded or welded steel pipe and
copper tube (copper not for ammonia)
• Interchangeable parts
• Easy to service
• Close coupled strainers, optional
• Many control variations are possible with the
use of a few Modules and kits. (See Adaptomode
Pressure Regulator Bul. 23-06)
• Stainless Steel Diaphragm
• Chrome Plated Pilot Seat
• Manual Opening Stem
Description
These compact, heavy duty, pilot operated, iron alloy (ASTM A126 Class
B) Outlet Pressure regulators are suitable for Ammonia, R-12, R-22,
R-502 and other common refrigerants and fl uids approved for use in
refrigerant valves. All A4 Regulators are pilot operated using upstream
Purpose
Modulates fl ow of refrigerant gas or liquid to maintain a constant down-
stream pressure as set-for, despite fl uctuations in load. The regulator
will gradually close when downstream pressure begins to rise above the
setting and will gradually open when pressure begins to fall below the
setting. The regulator cannot maintain set-for pressure if uncontrolled
branch pipe lines feed into the main pipeline downstream of the A4AO
Regulator. Typical uses are as follows:
Protect Compressor Motor from Overload (Hold-back):
See capacity
ratings in Condensed Catalog CC-11. Select at design parameters i.e.,
tons, evaporator temp./press and pressure drop.
Hot Gas Bypass Capacity Control:
See Bulletin BYG-4, Condensed
Catalog CC-11.
Limit Refrigerant Pressure in a Liquid Line:
Contact factory for selec-
tion assistance.
Prevent Deep Vacuum in Booster Suction:
See capacity ratings Con-
densed Catalog CC-11 “Compressor Suction Loading”. For selections
other than those shown, contact factory.
Prevent Pressure Rise in Suction Main:
Select valve based on mass fl ow
requirements. Valve Cv and pressure drop across regulator. Contact
factory for proper selection assistance, if required.
Hot Gas Defrost Control:
Refer to Condensed Catalog CC-1 1 and
Bulletin 90-10 for ratings and application information.
pressure for the opening force and requires a minimum 0.14 bar (2 psig)
pressure drop to fully open.
These valves are generally ordered with close coupled strainer to
prevent entrance of foreign material into the valve and the rest of the
system. (See current Bulletin 00-10 for strainer information.)
The fl uid temperature range for the A4 Series of Regulators is -45°C
to 105°C (-50°F to 220°F).
050321
PILOT PLUG
I S O 9 0 0 0 - 2 0 0 0 C E R T I F I E D
